Ghasemi Mehri, Zhang Yurou, Zhou Chunhua, Tan Cheng, Choi Eunyoung, Yun Jae Sung, Du Aijun, Yun Jung-Ho, Jia Baohua, Wen Xiaoming
Centre for Translational Atomaterials, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia.
Nanomaterials Centre, School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD, 4072, Australia.
Small. 2022 May;18(21):e2107680. doi: 10.1002/smll.202107680. Epub 2022 Apr 28.
Charge carrier transport in materials is of essential importance for photovoltaic and photonic applications. Here, the authors demonstrate a controllable acceleration or deceleration of charge carrier transport in specially structured metal-alloy perovskite (MACs)PbI (MA= CH NH ) single-crystals with a gradient composition of CsPbI /(MA Cs )PbI /MAPbI . Depending on the Cs-cation distribution in the structure and therefore the energy band alignment, two different effects are demonstrated: i) significant acceleration of electron transport across the depth driven by the gradient band alignment and suppression of electron-hole recombination, benefiting for photovoltaic and detector applications; and ii) decelerated electron transport and thus improved radiative carrier recombination and emission efficiency, highly beneficial for light and display applications. At the same time, the top Cs-layer results in hole localization in the top layer and surface passivation. This controllable acceleration and deceleration of electron transport is critical for various applications in which efficient electron-hole separation and suppressed nonradiative electron-hole recombination is demanded.
材料中的载流子传输对于光伏和光子应用至关重要。在此，作者展示了在具有CsPbI₃/(MAₓCs₁₋ₓ)PbI₃/MAPbI₃梯度组成的特殊结构金属合金钙钛矿（MACs）PbI₂（MA = CH₃NH₃）单晶中，载流子传输的可控加速或减速。根据结构中的Cs阳离子分布以及因此的能带排列，展示了两种不同的效应：i）由梯度能带排列驱动的电子在深度方向上的显著加速传输以及电子 - 空穴复合的抑制，这有利于光伏和探测器应用；ii）电子传输减速，从而提高辐射载流子复合和发射效率，这对光和显示应用非常有益。同时，顶部的Cs层导致空穴在顶层的定位和表面钝化。这种载流子传输的可控加速和减速对于各种需要有效电子 - 空穴分离和抑制非辐射电子 - 空穴复合的应用至关重要。
