A5054714234- Perovskite Materials and Applications
- Conducting polymers and applications
- Organic Light-Emitting Diodes Research
- Advanced Thermoelectric Materials and Devices
- Thermal Expansion and Ionic Conductivity
- 2D Materials and Applications
- Semiconductor Quantum Structures and Devices
- Chalcogenide Semiconductor Thin Films
- Organic Electronics and Photovoltaics
- Solid-state spectroscopy and crystallography
- Nanotechnology research and applications
University of Hong Kong
2021-2025
Chinese University of Hong Kong
2023
In addition to the broadly anticipated use of metal halide perovskites in photovoltaics and light-emitting devices, they also hold a great promise as cost-effective thermoelectrics, may offer an ultra-low thermal conductivity combined with high Seebeck coefficient. This Review summarizes recent advances theoretical analysis experimental studies thermoelectric properties these materials, particular focus on organic–inorganic (hybrid) low-dimensional analogues. After short introduction figures...
Flexible perovskite solar cells (fPSCs) prepared on flexible plastic substrates exhibit poor stability under illumination in ambient, due to inferior gas barrier properties of substrates. Herein, we investigated effect different modifications the back surface substrate improve ambient. T 80 simulated at maximum power point ambient (ISOS‐L‐1) can be increased from h over 350 with deposition a single layer (by spin‐coating or by atomic (ALD)). While ALD layers resulted best value and...
Abstract It is generally difficult to achieve high quality in low‐n‐value (MA‐free) FA‐based Dion‐Jacobson (DJ) 2D perovskites due their low crystallinity, random well‐width distribution of multiple quantum wells (QWs) with disordered orientation, which has seriously hindered further advances photovoltaics. Meanwhile, pure‐phase DJ uniform QWs width and fixed low‐n values are highly desirable for efficiency stability. Herein a novel 4APP(FA) 3 Pb 4 I 13 ‐based quasi‐DJ‐2D perovskite...
2D lead halide perovskites are used to improve device operational stability due increased environmental and reduced ion migration compared 3D perovskites. However, the relationship between perovskite under illumination spacer cation is still not well understood. Thus, we examine photoinduced segregation (PHS) in different mixed-halide show that PHS suppressed materials which have photostable bromide phase. As cations provide barrier perovskites, would be facilitated by loss of through their...
Abstract The performance of perovskite solar cells has significantly improved over the years in part due to defect passivation bulk and at interfaces. While many additive molecules have been reported literature, they are commonly applicable only one particular composition. Here we investigate a multifunctional additive, 4‐amino‐5‐bromo nicotinic acid (ABrNA), for use both methylammonium (MA)‐free perovskites with different Br content (bandgaps ranging from 1.53 1.73 eV) as well MA‐containing...
Photoinduced halide segregation (PHS) is a process of critical importance for the performance perovskite solar cells with mixed absorber layers. However, PHS still not well understood, especially in case layered perovskites (MHPs), which are less commonly studied compared to their 3D counterparts. Here, we investigated temperature- and light-induced 2D MHPs phenylpropylammonium (PPA) spacer. We found that PPA-based exhibited complex behavior dependence on temperature illumination intensity...
We investigated the influence of two passivating molecules containing a P═O group on performance quasi-2D Dion-Jacobson halide perovskite light-emitting diodes, namely, triphenylphosphine oxide (TPPO) and diphenyl-4-triphenylsilylphenyl phosphine (TSPO1). found that both lead to increased efficiency compared control devices, while they had opposite effects device lifetime, with decrease observed for TPPO an increase TSPO1. The resulted in differences energy-level alignment, electron...
As an emerging candidate material for photovoltaic applications, metal halide perovskites are well-known their high power conversion efficiency and fabrication convenience. Mixed-halide perovskites, specifically those with bromide (Br) iodide (I) anions, a popular choice the light-absorbing layer due to wide bandgap, critical consideration as perovskite-based tandem solar cells make major effort towards commercialization. However, photo-induced phase segregation in mixed under illumination...
Perovskite solar cells (PSCs) have gained significant attention as a promising photovoltaic technology due to their excellent power conversion efficiency (PCE) and cost-effective fabrication methods. However, ensuring long-term stability addressing environmental concerns are vital challenges for successful commercialization. In this study, we explore metal oxide-based thin film encapsulation methods enhance the performance durability of PSCs. We considered back surface modification flexible...
2D metal halide perovskites have enabled significant stability improvements in perovskite devices, particularly resistance to moisture. However, some are even more susceptible photooxidation compared 3D perovskites. This is true for commonly investigated Ruddlesden-Popper (RP) that exhibit increased susceptibility photoinduced degradation Dion-Jacobson (DJ) Comparisons between different RP and DJ reveal this phenomenon cannot be explained by proposed differences superoxide ion generation,...
Mixing Spacer Cations to Control Luminance and Stability of Quasi-2D PerovskitesZhilin Ren a, Muhammad Umair Ali Aleksandra B. Djurišić aa Department Physics, The University Hong Kong, KongMaterials for Sustainable Development Conference (MATSUS)Proceedings MATSUS Spring 2024 (MATSUS24)#2Dpero - 2D perovskites: chemical versatility, photophysics applicationsBarcelona, Spain, March 4th 8thOrganizers: Claudio Quarti Yana VaynzofOral, Ali, presentation 477DOI:...