The world energy crisis, as well as global warming, has intensified an urgent need for renewable energies. Solar radiation can be converted to electricity by solar cells readily; however, the high cost of photovoltaic systems has hindered its worldwide commercialization. Also, the solar cells cannot be integrated directly to skyscrapers. Therefore, luminescent solar concentrators have been developed. Here, we have proposed a novel and exciting structure for LSCs based on four different groups of QDs (generally superposition of QDs) with different sizes and materials to absorb photons from sunlight ranging from ultraviolet to near-infrared and then guide re-emitted photons to edge of LSC, which culminate in capturing photons by solar cells. We designed the QDs such that the absorption and emission spectra have minimum overlap leading to limited reabsorption losses. A Monte-Carlo ray-tracing simulation has been developed to model and evaluates the effectiveness of the proposed device. Then, we have optimized the QD’s concentration and LSC geometry to achieve maximum optical efficiency. For different quantum yields ranging from 0.4 to 1, we have obtained theoretically super high optical efficiency of 11–31%. The optimization results show a 67.8% enhancement in optical flux gain leading to 3.72-times more concentrated photon flux demonstrating our device’s commercialization potential. Besides, total absorbed photons, transparency, and ultimate fate of all photons were calculated. Finally, the proposed idea can be used to introduce a high-efficiency solar concentrator while extending the coverage of solar cells to make green energy.
... Three, the photon is re-absorbed by the other nanoparticle, for which this mechanism is known as re-absorption. Different events in Figure 3 for incident photons can be described as follows: [37] (1) The photon passes through the cylinder without being absorbed by the nanoparticles (transmission losses). (2) The photon is absorbed by the nanoparticle and then is emitted and escapes from the cylinder because its incident angle with the surface is smaller than the critical angle (transmission losses). ...
... In applied mathematics and engineering, a Monte-Carlo technique is an approach that generates random numbers in an attempt to solve a problem. It can be used in cases where a deterministic algorithm cannot be used or where the variables of the problem have coupled degrees of freedom [37][38][39]. ...
... Equation (3) shows how to calculate PDF [37]. ...
In high-speed wireless communication, visible light communication is considered an emerging and cutting-edge technology. A light-emitting diode can serve both as an illumination source in an environment and as a data transmitter. Nevertheless, plenty of complications stand in the way of developing VLC technology, including the low response time of waveguides and detectors and the field of view dependence of such devices. To cover those challenges, one approach is to develop a superior optical antenna that does not have a low response time related to phosphorescence materials and should also support concentrating light from the surroundings with a wide field of view. This research paper presents an optimized cylindrical optical antenna with benefits, such as affordable cost, fast response time due to high-efficient nanomaterials, and a wide field of view (FOV). The proposed structure avoids the need for intricate tracking systems and active pointing to the source, but it can also be integrated into portable devices. For the analysis of nanomaterials’ characteristics, finite difference time domain simulations are used, and Monte-Carlo raytracing is used to study the proposed optical antenna. It was found that the antenna’s optical efficiency varies from 1 to 29% depending on the size and the number of nanomaterials inside. Compared to other works, this paper shows higher efficiencies and wider FOV.
... Since white LEDs have such a broad spectrum that only a fraction of their spectrum is absorbed by one type of QD, we have used three various QDs. One of the most prevailing loss mechanisms in the LSC is mismatching between light spectrum and active optical centers because the mismatched part of the spectrum remains unabsorbed and consequently does not become involved in output efficiency [38]. Additionally, efficiency is the most dominant factor in measuring the performance of this system [38]. ...
... One of the most prevailing loss mechanisms in the LSC is mismatching between light spectrum and active optical centers because the mismatched part of the spectrum remains unabsorbed and consequently does not become involved in output efficiency [38]. Additionally, efficiency is the most dominant factor in measuring the performance of this system [38]. To address these problems, we apply the superposition method to cover the white LED spectrum and increase efficiency as well. ...
... However, despite having upsides-such as high photoluminescence quantum yield (PLQY) (i.e., the number of emitted photons per absorbed photons in the luminescent material [1]), large absorption coefficient, easy availability, good solubility, and low cost [41]-organic dyes suffer from narrow absorption spectra and unfriendly photodegradation [1]. During the last decade, QDs have been pursued as an outstanding fluorophore for LSCs thanks to their excellent spectral tunability, highly efficient photoluminescence, stability, broadband absorbance, and high quantum yield (QY), which is defined by the ratio of the emitted photons to the absorbed photons in the QD [38,51]. ...
Visible light communication (VLC) is a versatile enabling technology for following high-speed wireless communication because of its broad unlicensed spectrum. In this perspective, white light-emitting diodes (LED) provide both illumination and data transmission simultaneously. To accomplish a VLC system, receiver antennas play a crucial role in receiving light signals and guiding them toward a photodetector to be converted into electrical signals. This paper demonstrates an optical receiver antenna based on luminescent solar concentrator (LSC) technology to exceed the conservation of etendue and reach a high signal-to-noise ratio. This optical antenna is compatible with all colors of LEDs and achieves an optical efficiency of 3.75%, which is considerably higher than the similar reported antenna. This antenna is fast due to the small attached photodetector—small enough that it can be adapted for electronic devices—which does not need any tracking system. Moreover, numerical simulation is performed using a Monte Carlo ray-tracing model, and results are extracted in the spectral domain. Finally, the fate of each photon and the chromaticity diagram of the collected photons’ spectra are specified.
... The general schematic of an LSC has been illustrated in different references. So far, several shapes and sizes of waveguides and different types of fluorophores and host matrixes have been investigated to evaluate LSC performances [32] in terms of optical efficiency and FOV [25]. Since they can concentrate both direct and diffuse intended light, no tracking system is required [32,33]. ...
... So far, several shapes and sizes of waveguides and different types of fluorophores and host matrixes have been investigated to evaluate LSC performances [32] in terms of optical efficiency and FOV [25]. Since they can concentrate both direct and diffuse intended light, no tracking system is required [32,33]. LSC with a communication purpose includes a thin host matrix doped with fluorophores and the photodetector of receiver mounted on one specific edge. ...
... TIR leads to trapping these re-emitted photons inside the optical waveguide and concentrating them onto the edge of the LSC device [31]. Eventually, part of the photons is collected by a photodetector attached to the specific narrow edge or small end facet of the LSC [11,32]. Since the 1970s, various types of fluorophores have been applied to enhance the optical efficiency of the LSC [31]. ...
Visible Light Communication (VLC) is an important emerging choice for high-speed wireless communication. In this perspective, light-emitting diodes as illuminators will be modulated to transmit data simultaneously. However, the receivers bring severe difficulties due to cost, response time, and sensitivity with a wide Field Of View (FOV). To avoid these problems, one approach is to apply a large area photodetector; however, this solution is slow and costly. Another method is to focus light on a fast photodetector by optical components, but the photodetector’s FOV decreases, resulting from the conservation of etendue. Another option is Luminescent Solar Concentrators (LSCs). This paper demonstrates a novel shape of LSC with advantages such as inexpensive, fast response time, small antenna area for VLC purposes with significant geometrical gain, FOV, and ultra-broad bandwidth. It does not require any complex tracking system and active pointing but, due to its tiny size, it can also be adapted in integrating and mobile devices. Numerical simulation is done using Monte-Carlo raytracing, and the results are demonstrated in the spectral domain. The optical efficiency of the proposed antenna is obtained at 1.058%, which is about 0.4% better than the efficiency levels reported in other works, and the geometric gain of the antenna is reported to be 44, which is significant.
... We examined the proposed idea to realize high efficient luminescent solar concentrator [5] and in the following figure, the proposed LSC including superimposed QDs is illustrated. Based on that idea, the efficiency of the LSC was reported more than 30% (Figure 4). ...
... Multi wavelength photodetector with multi-electrical output is another most important application that can be realized using this idea [4]. High-efficiency solar concentrator based on superimposed QDs is introduced in [5]. Other interesting applications can be realized using the proposed idea too. ...
... Superimposed QDs based high efficiency luminescent solar concentrator[5]. ...
As everybody knows that electron, phonon, and photon transport in solids (crystals) depends on lattice physical properties. Manipulation of propagation properties needs to manipulate crystal parameters such as lattice constant, atoms in the lattice, etc. There are a limited number of crystalline structures in nature to manipulate charge, phonon, and photon transfer in electronics, acoustics, and photonics. The basic problem is how one can make single crystals with desired charge, phonon, and photon transfer performance? Also, how one can manipulate the mechanical, optical, and electrical performance of a device? It seems that nanotechnology and especially nanoparticles and superimposed nanocrystals can help to solve this problem. In this short letter, the superposition of Quantum Dots as a solution to enhance the capability of device designers in this regard is presented, discussed, and demonstrated by simple numerical simulation. If we use the superimposition of QDs, we can realize multi wavelength lasers in a single cavity [1,2]. The ultra-broadband semiconductor optical amplifiers can be implemented by this idea [3]. Multi wavelength photodetector with multi-electrical output is another most important application that can be realized using this idea [4]. High-efficiency solar concentrator based on superimposed QDs is introduced in [5]. Other interesting applications can be realized using the proposed idea too. All these advantages are related to optical and electrical properties dependency on the size of nanocrystals [6]. So, it is possible to make different crystals using the superimposition of well-known crystals. To demonstrate that, first, by choosing different crystals, and using the superposition of those, it is shown that the obtained structure is similar to a new crystal with a lattice constant that depends on initial superimposed crystal lattice constants as well as a geometrical combination of those. In the second part, we show that using colloidal QDs, it is so easy to combine different QDs with different sizes in a unique solution and a superimposed QDs with the desired density of each QDs will be available.
... A semi-infinite gold layer is used as the substrate. > REPLACE THIS LINE WITH YOUR MANUSCRIPT ID NUMBER (DOUBLE-CLICK HERE TO EDIT) < emerges as a promising candidate for diverse applications, encompassing ultrafast photodetectors, modulators, solar cells, and optical absorbers [43][44][45][46][47]. Graphene exhibits efficient absorption primarily owing to its thickness; however, relying solely on the overall absorption of an entire graphene structure may prove inadequate. ...
... Despite these shifts, the proposed absorbers demonstrate remarkable resilience in maintaining high absorption levels. The absorption rate exceeds 90%, even at incident angles as steep as approximately 46,47,49,50,52,55,57,58, and 60 degrees for structures (a), (b), (c), (d), (e), (f), (g), (h), and (i) respectively. These findings hold importance as they validate the robustness and applicability of our PA designs. ...
This paper presents the tunable and switchable Perfect Absorbers (PAs), operating within the mid-infrared (mid-IR) spectrum, specifically targeting the 3 to 5 µm range with precise 0.25 µm intervals. This spectrum is particularly engineered for its minimal atmospheric absorption and unique atmospheric transmission characteristics. Our approach utilizes graphene-based nanophotonic aperiodic multilayer structures optimized through the synergy of micro-genetic optimization algorithm (GOA) within an inverse design framework. This strategic combination enables a predictive model-based strategy that broadens the design of space exploration, facilitating the discovery of PAs with highly accurate absorption control. Employing the Transfer-Matrix-Method (TMM) method for simulations, we manipulate the absorption characteristics, allowing for the precise tailoring of the desired spectral response while maintaining the multilayer structures’ thickness under 2 µm. Our results demonstrate the tunability and switchability of PAs by adjusting graphene layers’ chemical potentials, highlighting their dynamic optical behavior. For instance, a PA optimized for a 4 µm absorption peak can shift its absorption peak to 4.22 µm by merely changing the graphene layer’s chemical potential from 0 eV to 1 eV, without compromising absorption efficiency. Additionally, our research uncovers the proposed absorbers’ remarkable adaptability to various incident angles, maintaining 90% absorption up to 52 degrees. This adaptability demonstrates the versatility and robustness of our design across a broad spectrum of real-world applications, including thermal photovoltaics, sensors, and stealth technology, where angular independence significantly enhances device performance and efficiency. This research not only deepens the understanding of nanophotonic materials’ capabilities but also paves the way for the design and development of highly efficient optical devices tailored for the mid-IR range.
... These properties offer opportunities to fabricate nearly lattice-matched high-quality PbSe/CdSe heterogeneous devices. CdSe has been widely used as the shell material for PbSe/CdSe core/shell colloidal quantum dots [25][26][27][28][29][30][31][32][33]. Two types of crystal structures, cubic zincblende and wurtzite hexagonal crystal structures, have been reported for CdSe with different bandgap energies [23,24,34]. ...
A novel Epitaxial Cadmium Selenide (CdSe) on Lead Selenide (PbSe) type-II heterojunction photovoltaic detector has been demonstrated by Molecular Beam Epitaxy (MBE) growth of n-type CdSe on p-type PbSe single crystalline film. The use of Reflection High-Energy Electron Diffraction (RHEED) during the nucleation and growth of CdSe indicates high-quality single-phase cubic CdSe. This is a first-time demonstration of single crystalline and single phase CdSe growth on single crystalline PbSe, to the best of our knowledge. The current–voltage characteristic indicates a p–n junction diode with a rectifying factor over 50 at room temperature. The detector structure is characterized by radiometric measurement. A 30 μm × 30 μm pixel achieved a peak responsivity of 0.06 A/W and a specific detectivity (D*) of 6.5 × 108 Jones under a zero bias photovoltaic operation. With decreasing temperature, the optical signal increased by almost an order of magnitude as it approached 230 K (with thermoelectric cooling) while maintaining a similar level of noise, achieving a responsivity of 0.441 A/W and a D* of 4.4 × 109 Jones at 230 K.
... Since PVC windows are entirely activated by PV cells, it is considered an active smart window. In the previous studies, PVC windows' energy efficiency is simulated and evaluated based on climate zones, their energy production, window-to-wall ratio (WWR), and window orientations [53][54][55][56][89][90][91][92][93]. Pierucci et al. (2018) studied photovoltachromic windows (PVC) in three regions, including BWh, Csa, and Cfb climates. ...
A facade can control interaction between the building and the environment. Advancements in control technologies and material science give the opportunity of using smart windows in a high-performance facade to improve the building’s energy performance and users’ comfort. This study aims to propose practical recommendations for smart windows’ implementation over various climate zones across the world. To follow this aim, 54 studies published from 2013 to 2022 collected from architecture, engineering, and material science databases and have been reviewed, and seven types of smart windows including electrochromic, photovoltachromic, gasochromic, thermochromic, photochromic, hydrochromic, and Low-E have been identified. Moreover, the thermal properties and visual features of smart coatings used in the windows and their impacts on energy efficiency and users’ comfort were recognized. Then, a comparative study was conducted to identify and propose the most efficient coating utilized in the structure of smart windows across different climate zones.
... The absorption enhancement depends on parameters such as the material of the metal and its location and size. Metallic NPs are utilized outside and inside the photoactive region (upper, middle, and bottom parts) (Jangjoy et al., 2019;Jangjoy et al., 2021;Heidarzadeh et al., 2015;Mirzaei et al., 2020;Chou and Chen, 2014;Heidarzadeh et al., 2022). The impact of incident light on metallic NPs and the interaction between incident light and free electrons of metals leads to surface oscillation of free electrons, which generally occurs at the plasma resonance frequency and leads to effects of localized surface plasmon resonance (LSPR). ...
Recently, thin-film organic–inorganic hybrid perovskite solar cells have a high efficiency-to-cost ratio. However, due to the thickness of the absorber layer, photon management in the absorber layer is still not optimized. This research suggests an embedded side for the plasmonic perovskite solar cells. Using Maxwell equations solver (finite-difference time-domain method), numerical optimization of photocurrent for gold, copper, silver, and aluminum cluster of nanoparticles in different geometries including quadrilateral, hexagonal, octagonal, and dodecagonal was investigated at a wavelength range from 300 nm to 800 nm. Moreover, the basic factors of optical simulation such as absorption coefficient, generation rate, and electric field distribution are shown in the optimal case, and the important parasitic absorption challenge for the cluster of nanoparticles was considered in the calculation of the net absorption. The reference cell uses a perovskite absorber (CH3NH3PbI3) with a thickness of 250 nm, which can significantly reduce the amount of lead, and the solar cell's toxicity. The photocurrent density for the optimized case utilizing spherical cluster of nanoparticles is obtained 21.74mAcm⁻², which is enhanced by approximately 25.6% compared to perovskite solar cells without nanoparticles. Finally, the best-case cluster nanoparticle is coated with an ultra-thin-film SiO2 layer, to help the chemical and thermal stability of metallic nanoparticles in the photoactive region. According to the final proposed model, the photocurrent of 22.28mAcm⁻² and enhancement of 28.72% were obtained. Besides, the proposed solar cell's open-circuit voltage, fill factor, and conversion efficiency are calculated at around 1.003 V, 0.88, and 19.71%, respectively.
In this paper, for the first time, a highly ultra-broadband QD-SOA based on superimposed Quantum Dots has been proposed to accomplish a broader optical gain spectra range of almost 3.5 µm from blue to Mid-infrared, considering solution-processed nanotechnology as a simple and cost-effective fabrication method. The realization of the ultra-broadband optical gain can be accomplished by the superimposition of the various size-distributed QD groups made of different materials in a way that the broader energy span is covered as a consequence of the variation of the bandgap energy for each QD groups. To this end, different QD groups made of Bismuth Tellurium Sulphide (Bi2Te3-xSx) and Cadmium Tellurium Sulphide (CdTe1-xSx) in the ZnS shell implemented in the active region of QD-SOA have been superimposed, in which the radii of each QD groups can be easily distributed due to incorporating solution-processed method. The performance of the proposed QD-SOA has been modelled based on the developed rate equation framework by assuming inhomogeneous broadening of energy levels as a result of the size distribution of QDs and the superimposition of various QD groups. Furthermore, the bandwidth and, the spectral range, and the flatness of the optical gain in the QD-SOA can be managed by the number of QD groups, the percentage of Tellurium and Sulphur in the Bi2Te3-xSx and CdTe1-xSx alloys, and the size distribution of each QD groups.
The demand for green energy is growing these days as a result of the world energy crisis, as well as global warming. Solar cells are in great interest due to the fact that solar energy can be easily converted to electricity, if the photovoltaic cell's cost can be lowered. One of the methods to make low-cost energy is using Luminescent solar concentrators. They have the advantage of directly integrating solar cells to dense urban areas as well as skyscrapers. Different materials and waveguide sizes have been investigated for use in luminescent solar concentrators. However, the optimized waveguide geometry and quantum dots concentrators have not been thoroughly studied. In this paper, we have simulated graphene quantum dots using density function theory. A Monte-Carlo ray-tracing simulation was developed to model our device. We have optimized the luminescent solar concentrator geometry by Monte-Carlo simulation. The optimization results show a 99% enhancement in the energy flux gain of the final device. Besides, we have calculated and analyzed the fate of all photons.
In this work, the optical gain engineering of an ultra-broadband InGaAs/AlAs solution-processed quantum dot (QD) semiconductor optical amplifier using superimposed quantum structure is investigated. The basic unit in the proposed structure (QDs) is designed and fabricated using solution-processed methods with considerable cost-effectiveness, fabrication ease, and QDs size tunability up to various limits (0.1 nm up to the desired values), considering suitable synthesis methods. Increasing the number of QDs, the device can span more than 1.02 μm (O, C, S, and L bands) using only one type of material for all QDs, and is not restricted to this limit in case of using more QD groups. Also, it can manipulate the optical gain peak value, spectral coverage, and resonant energy for customized optical windows, among which 1.31 μm and 1.55 μm are simulated as widely-applicable cases for model validation. This makes the device a prominent candidate for ultra-wide-bandwidth and also customized-gain applications in general. Variation impact of homogeneous and inhomogeneous broadenings, injection current and number of QD groups on optical gain are explained in detail. Besides proposing a design procedure for implementation of an ultra-broadband optical gain using superimposed QDs in solution-processed technology, the proposed gain engineering idea using this technology provides practically infinite bandwidth and an easy way to realize. By introducing this idea, one more step is actually taken to approach the effectiveness of solution process technology.
A novel type of transparent monitor with high-resolution images based on Si-SiO2 core-shell nanoparticles is presented in this contribution. In this monitor, a quasi-array of nanoparticles was used to obtain a very sharp scattering profile. For this purpose, the Si-SiO2 nanoparticles were synthesized and with controlling the size of particles, the dominant emission wavelength was controlled. For the fabrication of a blue color transparent monitor the solution processed Si-SiO2 nanoparticles were dispersed in polystyrene and then coated on a transparent glass surface. After drying the film, the typical features representing a transparent monitor were studied. A video projector was used and text and pictures were sent on the monitor. This monitor reveals very attractive features such as simplicity, wide viewing angle, scalability to larger sizes and low cost. Importantly, the texts and pictures can be well presented on both sides of the fabricated monitor. The composite thin film can be also separated from the glass and can be used as a flexible display. To shed light on the impact of the structure on the optical properties Si-SiO2 and Ag nanomaterials representing perfect arrays of nanoparticles, quasi-arrays and randomly oriented nanoparticles were calculated/simulated using the finite-difference time-domain (FDTD) method. The results were compared to the experimental data and show a high accordance.
Featured Application: Off-grid infrastructural installations powered by solar windows. Abstract: A study of photovoltaic solar window technologies is reported and it focuses on their structural features, functional materials, system development, and suitability for use in practical field applications including public infrastructures and agricultural installations. Energy generation performance characteristics are summarized and compared to theory-limit predictions. Working examples of pilot-trial solar window-based installations are described. We also report on achieving electric power outputs of about 25 W p /m 2 from clear and transparent large-area glass-based solar windows.
Technical Report "Global Energy System based on 100% Renewable Energy – Power Sector", published at the Global Renewable Energy Solutions Showcase event (GRESS), a side event of the COP23, Bonn, November 8, 2017
A global transition to 100% renewable electricity is feasible at every hour throughout the year and more cost effective than the existing system, which is largely based on fossil fuels and nuclear energy. Energy transition is no longer a question of technical feasibility or economic viability, but of political will.
Existing renewable energy potential and technologies, including storage can generate sufficient and secure power to cover the entire global electricity demand by 2050 . The world population is expected to grow from 7.3 to 9.7 billion. The global electricity demand for the power sector is set to increase from 24,310 TWh in 2015 to around 48,800 TWh by 2050.
Total levelised cost of electricity (LCOE) on a global average for 100% renewable electricity in 2050 is 52 €/MWh (including curtailment, storage and some grid costs), compared to 70 €/MWh in 2015.
Solar PV and battery storage drive most of the 100% renewable electricity supply due to a significant decline in costs during the transition.
Due to rapidly falling costs, solar PV and battery storage increasingly drive most of the electricity system, with solar PV reaching some 69%, wind energy 18%, hydropower 8% and bioenergy 2% of the total electricity mix in 2050 globally.
Wind energy increases to 32% by 2030. Beyond 2030 solar PV becomes more competitive. Solar PV supply share increases from 37% in 2030 to about 69% in 2050.
Batteries are the key supporting technology for solar PV. Storage output covers 31% of the total demand in 2050, 95% of which is covered by batteries alone. Battery storage provides mainly short-term (diurnal) storage, and renewable energy based gas provides seasonal storage.
100% renewables bring GHG emissions in the electricity sector down to zero, drastically reduce total losses in power generation and create 36 million jobs by 2050.
Global greenhouse gas emissions significantly reduce from about 11 GtCO2eq in 2015 to zero emissions by 2050 or earlier, as the total LCOE of the power system declines.
The global energy transition to a 100% renewable electricity system creates 36 million jobs by 2050 in comparison to 19 million jobs in the 2015 electricity system. Operation and maintenance jobs increase from 20% of the total direct energy jobs in 2015 to 48% of the total jobs in 2050 that implies more stable employment chances and economic growth globally.
The total losses in a 100% renewable electricity system are around 26% of the total electricity demand, compared to the current system in which about 58% of the primary energy input is lost.
Fluorinated graphene quantum dots (F-GQDs) were prepared by mixing GQDs and XeF 2 in a facile gaseous phase heating method. The F-GQDs with excellent water solubility have a F/C atomic ratio of 84.25% and a diameter of 2–6 nm. The photoluminescence (PL) properties of GQDs and F-GQDs were investigated systematically. The results showed that the PL emission of the F-GQDs exhibited an obvious blue-shift of 90 nm compared to that of the GQDs.
In this paper, the multi-wavelength solution-processed quantum dot laser has been proposed by the superimposed quantum dots. To this end, the rate equation framework has been developed to model the simultaneous lasing in desired wavelengths by considering inhomogeneous broadening of energy level as a result of the size distribution of quantum dots and the homogeneous broadening due to the carries scattering inside quantum dots. Moreover, the solution process technology has been utilized in order to synthesize the quantum dots in various sizes according to the desired wavelengths. The simulation results show that simultaneous lasing has been realized by superimposition of two sizes of InGaAs quantum dots in a single cavity at two wavelengths of 1.31μm and 1.55μm which have special importance in telecommunication applications. Besides, the output power intensity at the desired wavelengths can be managed by controlling the density of quantum dots.
Building-integrated sunlight harvesting utilizing laminated glass luminescent solar concentrators (LSCs) is proposed. By incorporating high quantum yield (>90%), NIR-emitting CuInS2/ZnS quantum dots (QDs) into the polymer interlayer between two sheets of low-iron float glass, a record optical efficiency of 8.1% is demonstrated for a 10 cm x 10 cm device that transmits ~44% of visible light. After completing prototypes by attaching silicon solar cells along the perimeter of the device, the electrical power conversion efficiency (PCE) was certified at 2.2% with a black background, and at 2.9% using a reflective substrate. This ‘drop-in’ LSC solution is particularly attractive because it fits within the existing glazing industry value chain with only modest changes to typical glazing products. Performance modeling predicts >1 GWh annual electricity production for a typical urban skyscraper in most major US cities, enabling significant energy cost savings and potentially ‘net-zero’ buildings.
The transition to fully energetically sustainable architecture through the realization of so-called net zero-energy buildings is currently in progress in areas with low population density. However, this is not yet true in cities, where the cost of land for the installation of ground photovoltaic (PV) is prohibitively high and the rooftop space is too scarce to accommodate the PV modules necessary for sustaining the electrical requirements of tall buildings. Thus, new technologies are being investigated to integrate solar-harvesting devices into building façades in the form of PV windows or envelope elements. Luminescent solar concentrators (LSCs) are the most promising technology for semi-transparent, electrodeless PV glazing systems that can be integrated ‘invisibly’ into the built environment without detrimental effects to the aesthetics of the building or the quality of life of the inhabitants. After 40 years of research, recent breakthroughs in the realization of reabsorption-free emitters with broadband absorption have boosted the performance of LSCs to such a degree that they might be commercialized in the near future. In this Perspective, we explore the successful strategies that have allowed this change of pace, examining and comparing the different types of chromophores and waveguide materials, and discuss the issues that remain to be investigated for further progress.
![Optical efficiency, the percentage of absorbed photons, and optical flux gain with optimized absorbance of 8. (A) Optical efficiency with respect to the absorbance (QD concentration) for an LSC of 6×6×0.15 [cm] (cyan), 12×12×0.3 [cm] (red), and 24×24×0.6 [cm] (yellow) dimensions, (B) the percentage of absorbed photons vs. geometric gain, (C) optical efficiency (cyan, left axis) and optical flux gain (red, right axis) with respect to different geometric gains to find the optimum geometric gain, (D) the percentage of absorbed photons for different LSC lateral sizes and the selected geometric gain (G=12), (E) optical efficiency and (F) optical flux gain swept by LSC lateral size for quantum yields of 0.4 (cyan), 0.6 (red), and 1 (yellow).](https://www.researchgate.net/profile/Milad-Rastkar-Mirzaei/publication/342157447/figure/fig1/AS:908717218332672@1593666476285/Optical-efficiency-the-percentage-of-absorbed-photons-and-optical-flux-gain-with_Q320.jpg)
