Zhang Yalan, Wen Jialun, Xu Zhuo, Liu Dongle, Yang Tinghuan, Niu Tianqi, Luo Tao, Lu Jing, Fang Junjie, Chang Xiaoming, Jin Shengye, Zhao Kui, Liu Shengzhong Frank
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Shaanxi Key Laboratory for Advanced Energy Devices, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China.
Dalian National Laboratory for Clean Energy, iChEM, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
Adv Sci (Weinh). 2021 Jul;8(13):e2001433. doi: 10.1002/advs.202001433. Epub 2021 May 24.
New structural type of 2D AA' M X type halide perovskites stabilized by symmetric diammonium cations has attracted research attention recently due to the short interlayer distance and better charge-transport for high-performance solar cells (PSCs). However, the distribution control of quantum wells (QWs) and its influence on optoelectronic properties are largely underexplored. Here effective phase-alignment is reported through dynamical control of film formation to improve charge transfer between quantum wells (QWs) for 2D perovskite (BDA)(MA) Pb I (BDA = 1,4-butanediamine, 〈n〉 = 4) film. The in situ optical spectra reveal a significantly prolonged crystallization window during the perovskite deposition via additive strategy. It is found that finer thickness gradient by n values in the direction orthogonal to the substrate leads to more efficient charge transport between QWs and suppressed charge recombination in the additive-treated film. As a result, a power conversion efficiency of 14.4% is achieved, which is not only 21% higher than the control one without additive treatment, but also one of the high efficiencies of the low-n (n ≤ 4) AA' M X PSCs. Furthermore, the bare device retains 92% of its initial PCE without any encapsulation after ambient exposure for 1200 h.
由对称二铵阳离子稳定的新型二维AA'MX型卤化物钙钛矿，因其层间距离短和电荷传输性能更好，近来在高性能太阳能电池（PSC）领域引起了研究关注。然而，量子阱（QW）的分布控制及其对光电性能的影响在很大程度上尚未得到充分探索。本文报道了通过动态控制成膜过程实现有效的相位排列，以改善二维钙钛矿（BDA）（MA）PbI（BDA = 1,4-丁二胺，〈n〉 = 4）薄膜量子阱之间的电荷转移。原位光谱显示，通过添加剂策略，在钙钛矿沉积过程中结晶窗口显著延长。研究发现，在垂直于基底方向上，n值形成的更精细厚度梯度导致量子阱之间更有效的电荷传输，并抑制了添加剂处理薄膜中的电荷复合。结果，实现了14.4%的功率转换效率，这不仅比未经添加剂处理的对照样品高出21%，也是低n（n≤4）AA'MX型PSC的高效值之一。此外，裸器件在环境暴露1200小时后，无需任何封装即可保留其初始PCE的92%。
