Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, P. R. China.
Small. 2023 Apr;19(17):e2207312. doi: 10.1002/smll.202207312. Epub 2023 Feb 1.
All-inorganic lead halide perovskite nanocrystals (NCs) emerge as a rising star in photovoltaic fields on account of their excellent optoelectronic properties. However, it still remains challenging to further promote photovoltaic efficiency due to the susceptible surface and inevitable vacancies. Here, this work reports a 3D/2D core/shell perovskite heterojunction based on CsPbI NCs and its performance in solar cells. The guanidinium (GA ) rich 2D nanoshells can significantly passivate surface trap states and lower the capping ligand density, resulting in improved photoelectric properties and carrier transport and diminished nonradiative recombination centers via the hydrogen bonds from amino groups in GA ions. Consequently, an outstanding power conversion efficiency (PCE) of up to 15.53% is realized, substantially higher than the control device (13.77%). This work highlights the importance of surface chemistry and offers a feasible avenue to achieve high-performance perovskite NCs-based optoelectronic devices.
全无机卤化铅钙钛矿纳米晶体 (NCs) 因其优异的光电性能，在光伏领域崭露头角。然而，由于其表面易受影响和不可避免的空位，进一步提高光伏效率仍然具有挑战性。在这项工作中，报告了一种基于 CsPbI NCs 的 3D/2D 核/壳钙钛矿异质结及其在太阳能电池中的性能。富含胍 (GA) 的 2D 纳米壳可以显著钝化表面陷阱态并降低覆盖配体密度，从而通过 GA 离子中氨基的氢键改善光电性能和载流子输运，并减少非辐射复合中心。因此，实现了高达 15.53%的出色功率转换效率 (PCE)，显著高于对照器件 (13.77%)。这项工作强调了表面化学的重要性，并为实现高性能钙钛矿 NCs 基光电器件提供了可行的途径。
