Tai Wu

UNSW Sydney | UNSW · School of Photovoltaic and Renewable Energy Engineering

CsPbI 3 perovskite quantum dot (PQD) shows high potential for next‐generation photovoltaics due to their tunable surface chemistry, good solution‐processability and unique photophysical properties. However, the remained long‐chain ligand attached to the PQD surface significantly impedes the charge carrier transport within the PQD solids, thereby pr...

Modulating perovskite crystallization and understanding hot carriers (HCs) dynamics in perovskite films are very critical to achieving high‐performance perovskite solar cells (PSCs). Herein, a small organic molecule (6BAS) with multisite anchors (C═O) as an efficient additive is introduced into PbI2 precursors to modulate perovskite crystallization...

Quasi-2D Dion-Jacobson (DJ) tin halide perovskite has attracted much attention due to its elimination of Van der Waals gap and enhanced environmental stability. However, the bulky organic spacers usually form a natural quantum well structure, which brings a large quantum barrier and poor film quality, further limiting the carrier transport and devic...

Organic small molecules have been proven to be the most efficient and predominantly employed hole transport layers (HTLs) in perovskite solar cells (PSCs), the reliance of HTLs on additives like Li‐TFSI has been unavoidable, particularly in terms of the well‐known Spiro‐OMeTAD. However, Li‐TFSI aggregation in HTL results in the decreased performanc...

The mismatched energy level alignment at the hole transport interface is recognized to be a prominent limitation for the Cs2AgBiBr6‐based perovskite solar cell (PSC) to achieve high power conversion efficiency (PCE) but has not been well investigated yet. In order to solve this problem to some extent, it is proposed to balance the energy offset at...

To elevate the performance and durability of perovskite solar cells, a holistic approach to mitigating defects throughout the device is essential. While advancements in refining top interfaces have been significant, the potential of stabilizing buried interfaces and grain boundaries has not been fully tapped. The research underscores the transforma...

2D Dion–Jacobson (DJ) tin halide perovskite shows impressive stability by introducing diamine organic spacer. However, due to the dielectric confinement and uncontrollable crystallization process, 2D DJ perovskite usually exhibits large exciton binding energy and poor film quality, resulting in unfavorable charge dissociation, carrier transport and...

Slowing hot carriers (HCs) cooling in lead halide perovskites is important to further push the efficiency of perovskite solar cells (PSCs). Herein, we found that the HCs cooling can be...

Compared with three-dimensional (3D) tin halide perovskite, quasi-two-dimensional (2D) tin halide perovskite shows high stability and low defect density by introducing bulky organic spacers, which is beneficial to realize efficient and stable tin perovskite solar cells (TPSCs). However, the competitive growth between low-dimensional and three-dimen...

We report an azide‐functionalized cobaloxime proton‐reduction catalyst covalently tethered into the Wurster‐type covalent organic frameworks (COFs). The cobaloxime‐modified COF photocatalysts exhibit enhanced photocatalytic activity for hydrogen evolution reaction (HER) in alcohol‐containing solution with no presence of a typical sacrificial agent....

We report an azide‐functionalized cobaloxime proton‐reduction catalyst covalently tethered into the Wurster‐type covalent organic frameworks (COFs). The cobaloxime‐modified COF photocatalysts exhibit enhanced photocatalytic activity for hydrogen evolution reaction (HER) in alcohol‐containing solution with no presence of a typical sacrificial agent....

The buried interface defects severely affect the further enhancements of efficiency and stability of SnO2-based planar perovskite solar cells (PSCs). To well tackle this problem, we propose a passivation strategy employing NH4PF6 to modify the buried interface of perovskite layer ((FAPbI3)0.85(MAPbBr3)0.15 composition) in planar PSCs. After introdu...

Lithium bis(trifluoromethanesulfonyl)imide (Li‐TFSI) has been identified as the most used and effective p‐dopant for hole transport layer (HTL) in perovskite solar cells (PSCs). However, the migration and agglomeration of Li‐TFSI in HTL negatively impact PSCs performance and stability. Herein, we report an effective strategy for adding a liquid cry...

Lithium bis(trifluoromethanesulfonyl)imide (Li‐TFSI) has been identified as the most used and effective p‐dopant for hole transport layer (HTL) in perovskite solar cells (PSCs). However, the migration and agglomeration of Li‐TFSI in HTL negatively impact PSCs performance and stability. Herein, we report an effective strategy for adding a liquid cry...

As an important category of photochemical reactions, photocyclization is regarded as an ideal entry point for building intelligent photoresponsive materials. Herein, a series of aggregation-induced emission luminogens (AIEgens) with sensitive photoresponsive behavior are developed based on 2,3-diphenylbenzo[b]thiophene S,S-dioxide (DP-BTO), and the...

The interface between the absorber and transport layers is shown to be critical for highly efficient perovskite solar cells (PSCs). The undesirable physical and chemical properties of interfacial layers often cause unfavorable band alignment and interfacial states that lead to high charge-carrier recombination and eventually result in lower device...

Harvesting hot carriers (HCs) before thermalizing to the perovskite crystal lattice is very promising for advancing the efficiency of perovskite solar cells (PSCs) towards the Shockley–Queisser limit. Thus, it is very crucial to slow down the HCs cooling process in lead halide perovskites. Herein, we investigated the HCs cooling dynamics of perovsk...

Surface defect passivation of perovskite films through chemical interaction between specific functional groups and defects has been proven to be an effective technique for enhancing the performance and stability of perovskite solar cells (PSCs). However, an in-depth understanding of how these passivation materials affect the intrinsic nature of cha...

Surface passivation engineering of perovskite films via organic functional small molecules has emerged as an effective strategy for improving the efficiency and stability of perovskite solar cells (PSCs). However, a systematic understanding of underlying mechanisms behind these improvements is still missing. In this work, two new naphthalimide‐base...

In inverted perovskite solar cells (PSCs), perovskite crystals grow on the bottom hole transporting layer (HTL), and the HTL not only functions to extract and transport holes, but also manipulates the perovskite crystallization process and affects perovskite film quality. Poly(triarylamine) (PTAA) represents one of the most widely used and highly-e...

Understanding the effect of additive on the interfacial charge‐carriers transfer dynamics is very crucial to obtaining highly efficient perovskite solar cells. Herein, we designed a simple additive, dimethyl oxalate (DO), functioning as an effective defect passivator of perovskite grain boundaries via the coordination interaction between the carbon...

Interfacial engineering for passivating perovskite surface defects and reducing nonradiative recombination loss has been proven to be an effective strategy to fabricate highly efficient and stable perovskite solar cells (PSCs). However, the detailed understanding of the original role of interface materials on the charge‐carriers transfer dynamics o...

Surface treatment of perovskite films with interface materials is effective strategy to resolve trap-mediated nonradiative recombination toward high efficiency and stability perovskite solar cells (PSCs). However, interface materials for multi-functional treatment have been rarely investigated in PSCs. In this work, a novel pyrene-based organic mat...

Here we report a mesoporous TiO2 with large specific surface area and rich oxygen vacancies using Ti-based MOF (MIL-125) as precursor through high-temperature annealing. Such integration of unique mesoporous structure...

Hole-transporting material (HTM) plays a paramount role in enhancing the photovltaic performance of perovskite solar cells (PSCs). Currently, the vast majority of these HTMs employed in PSCs are organic small molecules and polymers, yet the use of organic metal complexes in PSCs applications remains less explored. To date, most of reported HTMs req...

Methoxy-free donors are an emerging class of alternative methoxy triphenylamine materials toward stable organic hole-transporting materials (HTMs). However, low cost, stable and efficient methoxy-free donors are scarce. Moreover, the lack of a molecular design strategy limits the further development of methoxy-free donor-based HTMs. This study repo...

Organic-inorganic halide perovskites (OIHPs) are nature-abundant raw materials with prospects as a low-cost renewable energy source encouraged by the solution-processed capability of OIHPs. However, the application of expensive hole transporting...

Hole-transport material (HTM) in perovskite solar cells (PSCs) plays a critical role in achieving high photovoltaic performance and long-term stability. Despite a great number of HTMs have been explored for perovskite solar cells (PSCs), only a few reported HTMs can comprehensively outperform the current state-of-the-art Spiro-OMeTAD. Moreover, fur...

Three cost-effective D-π-D hole transport materials (HTMs) with different π-bridge including biphenyl (SY1), phenanthrene (SY2) and pyrene (SY3) have been synthesized by one-pot reaction with cheap commercially available starting materials for application in organic-inorganic hybrid perovskite solar cells (PSCs). The effect of the various π-bridge...

Bis[di(4-methoxyphenyl)amino)]carbazole-capped indacenodithiophene (IDT) has been constructed as hole transport materials (HTMs) for perovskite solar cells (PSCs). Two IDT-based HTMs, one with 3,6-bis[di(4-methoxyphenyl)amino)carbazole (YK1) and another with 2,7-bis[di(4-methoxyphenyl)amino)carbazole (YK2), show different performances in PSCs. PSCs...

Hole-transport material (HTM) plays a crucial role in determining the photovoltaic performance and long-term stability of perovskite solar cells (PSCs), because they not only efficiently facilitate hole-extraction and tranfer, but also act as a barrier to protect perovskite from moisture and oxygen. So far, the power conversion efficiencies (PCEs)...

Hole-transport materials (HTMs) play an important role in the most highly performing perovskite solar cells (PSCs). In the work, for the first time, an efficient cyclopenta[hi]aceanthrylene-based dopant-free D-A-D typed hole transport material (HTM) YN3 is developed for the application in organic-inorganic hybrid and all-inorganic perovskite solar...