Investigating heterogeneity and its impact on metal halide perovskite photovoltaics

金属卤化物钙钛矿光致发光材料是一种新的光伏技术，具有超越传统光致发光材料的潜力，并加速我们向净零的进展。二维（2D），层状，金属卤化物钙钛矿（2D-MHP）是一种非常令人兴奋，但研究不足的钙钛矿半导体，具有高稳定性与高性能相结合的前景。由于2D钙钛矿结构允许有机阳离子，数十亿的结构是可能的，为我们提供了一个可调的电子和结构特性。然而，基于纯2D-钙钛矿的光伏器件尚未接近理论上可实现的那些。这是由于电荷提取问题，这是有机阳离子的绝缘性质与不良取向的微观结构相结合的结果。在2D-MHPs中电荷传输的基本物理过程还未被充分研究，并且在确定光伏性能方面至关重要。这个项目将寻求克服这些挑战，通过发展的影响电荷提取的因素的理解，特别是集中在调查这些系统的异质性。该项目将研究一系列当前最先进的2D钙钛矿的结构和电荷载流子动力学，并使用这种理解来预测阳离子化学结构的所需变化，这将直接导致改善电荷传输和光伏性能。这种理解将用于合成新的2D钙钛矿，并使用它们来制造高性能光伏器件。

Metal halide perovskite photovoltaics are a new photovoltaic technology with the potential tooutperform conventional photovoltaics and accelerate our progress towards net-zero. Twodimensional (2D), layered, metal halide perovskites (2D-MHPs) are an extremely exciting,but understudied, class of perovskite semiconductors that hold the promise of combininghigh-stability with high-performance. Since the 2D perovskite structure admits organiccations, billions of structures are possible, offering us a tunable handle on electronic andstructural properties. However, photovoltaic devices based on pure 2D-perovskites have yetto reach close to those which are theoretically achievable. This is due to charge extractionissues, a result of the insulating properties of the organic cation, combined with poorlyoriented microstructure. The fundamental physical processes governing charge transport in the 2D-MHPs areunderexplored and are critical in determining photovoltaic performance. This project will seekto overcome these challenges by developing an understanding of the factors which affectcharge extraction, focussing in particular on investigating the heterogeneity of thesesystems. This project will investigate the structure and charge carrier dynamics of a range ofcurrent state of the art 2D-perovskites and use this understanding to predict requiredchanges to the cation chemical structures which will lead directly to improved chargetransport, and photovoltaic performance. This understanding will then be used to synthesisenew 2D-perovskites and use them to fabricate high performance photovoltaic devices.