2D-3D复合钙钛矿电池中铜基硫化物空穴传输材料的性能调控研究

Perovskite solar cells (PVSCs) have made great achievements in recent years. However, the stability of PVSC devices is still unsatisfactory and is the main bottleneck impeding their commercialization. In this proposal, we propose that stable inorganic copper-based chalcogenides can be fabricated through e-beam thermal evaporation method. And their energy band positions and optical-electrical properties can be further modulated to work as efficient hole transport layers (HTLs) for 2D-3D hybrid PVSCs. We aim at studying PVSCs based on modulated copper-based chalcogenides (m-CuxS) HTL with architecture of transparent electrode/SnO2 electron transport layer/2D-3D hybrid perovskite/m-CuxS HTL/Metal electrode. We propose that the energy band positions and optical-electrical properties of CuxS can be engineered or modulated by elemental doping and surface passivation strategy. Prudent doping of Al, or O and surface passivation by SiO2 are expected to change the electronic structure, carrier density, energy band position, hole mobility and defect density of CuxS HTL. We will devote to studying the fabrication, energy band alignment and optical-electrical properties of m-CuxS HTLs and we will also focus on the performance optimization of PVSC devices. Ultimately, we plan to achieve 2D-3D hybrid PVSCs with high power conversion efficiency (PCE) over 21%, high humidity stability and high light soaking stability. The effects of elemental doping and surface passivation on energy band alignment and optical-electrical properties of m-CuxS will be studied systematically. And the basic scientific issues regarding PCE optimization, charge transfer properties and stability issues in m-CuxS based 2D-3D hybrid solar cells will also be studied systematically.

钙钛矿太阳能电池近年来取得了很大进展，然而，电池的稳定性问题仍未得到解决并且已经成为阻碍钙钛矿电池产业化的主要瓶颈。本申请提出利用电子束蒸发法制备稳定的无机铜基硫化物空穴传输材料并对其进行性能调控，将性能调控的铜基硫化物(m-CuxS)材料作为正置结构2D-3D复合钙钛矿电池的空穴传输层，构筑稳定高效的2D-3D复合钙钛矿光伏器件。提出通过元素掺杂(Al、O掺杂)和表面钝化(SiO2表面钝化)技术手段协同调控铜基硫化物的原子价轨道分布、载流子浓度、能带位置、电导率、空穴迁移率和表面缺陷等材料特性。研究空穴传输材料的工艺实现和性能调控，研究基于无机m-CuxS空穴传输层的钙钛矿电池的性能优化，开发出光电转换效率达21%的钙钛矿电池，器件具有很好的湿度和光照稳定性。揭示铜基硫化物的性能调控的物理机制，揭示铜基硫化物的性能调控对器件光伏性能、电输运特性和稳定性的影响机制。

推动绿色发展，实现“碳达峰，碳中和”的宏伟目标，必须大力发展光伏技术等绿色能源。铅(Pb)基有机金属卤化物钙钛矿电池的光伏转换效率已经从3.8%提升到了25.7%，表现出具有巨大的发展潜力和应用前景。未来钙钛矿电池科学研究的两大重要任务是提升钙钛矿电池的稳定性和解决重金属Pb的毒性问题。. 本项目集中研究铅基钙钛矿电池的缺陷调控及界面优化，无铅钙钛矿新材料开发和器件的性能优化两大内容。系统研究钙钛矿器件中的材料优化、性能改进、电输运特性和稳定性等基本科学问题，开发新型无铅钙钛矿材料，调控材料光电特性，制备并优化无铅光伏/探测器件。研究发现：二氧化硅低聚物可以原位钝化钙钛矿缺陷，提升器件效率和稳定性；电子束蒸发SiO2可以有效钝化钙钛矿与电子传输层界面；三元金属氧化物Fe1-xMgxO3可以有效控钙钛矿生长及钙钛矿/ETL界面；PFN-Br和胍氢碘酸盐（GAI）可以协同提升钙钛矿电池效率及稳定性；新型结构的2D钙钛矿可以有效减小钙钛矿电池能量损失，实现22.8%转换效率；苯胺次磷酸盐可以提升无铅锡基钙钛矿电池的效率和稳定性；通过元素掺杂可以有效降低Cs2AgBiBr6的禁带宽度至1.62 eV，也可以通过元素掺杂在不改变禁带宽度的情况下实现1000 nm的红外探测。上述研究系统揭示了影响铅基钙钛矿电池的电输运特性，缺陷调控，性能优化的关键因素，提出了制备高效稳定钙钛矿光伏器件的关键技术，并在无铅钙钛矿材料的设计、制备及光电器件的性能优化方面积累了研究基础，为后续发展提供了思路。