Chen Shuang, Pan Lu, Ye Tao, Lei Nuo, Yang Yijun, Wang Xi
Department of Physics, School of Science, Key Laboratory of Luminescence and Optical Information, Ministry of Education, Beijing Jiaotong University Beijing 100044 China
RSC Adv. 2021 Jan 20;11(7):3997-4005. doi: 10.1039/d0ra09294k. eCollection 2021 Jan 19.
Inorganic-organic hybrid perovskite solar cells (PSCs) have stirred up a new research spree in the field of photovoltaics due to its high photoelectric conversion efficiency and simple preparation process. In recent years, the research of inorganic-organic hybrid PSCs has been widely reported, among which FA/Cs PSCs are especially outstanding. However, there are few reports explaining the lattice structural change mechanism of Cs FA PbIBr PSCs from the view of chemical bonds. In this work, a facile method of 15% Cs cations partially substituting FA cations has been presented to enhance the structural stability and photovoltaic performances of FAPbIBr PSCs. The partial incorporation of Cs in FAPbIBr resulted in a more beneficial tolerance factor and inhibited the deep defect state of elemental Pb. More importantly, it inhibited the phase transition from the cubic black α-phase to the hexagonal yellow δ-phase of FAPbIBr. Moreover, the power conversion efficiency (PCE) of CsFAPbIBr PSCs achieved a substantial improvement. The stability also achieved a remarkable promotion, which was demonstrated by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Nuclear Magnetic Resonance (NMR). These analyses indicate that 15% Cs can induce the lattice shrinkage, reduce the specific traps and inhibit the phase transition, thus improving the structural stabilities of CsFAPbIBr PSCs under atmosphere and calefaction. These results provide an effective way for fabricating stable and efficient inorganic-organic perovskite solar cells with promising properties.
无机-有机杂化钙钛矿太阳能电池（PSCs）因其高光电转换效率和简单的制备工艺，在光伏领域掀起了新一轮的研究热潮。近年来，无机-有机杂化PSCs的研究已有广泛报道，其中FA/Cs PSCs尤为突出。然而，从化学键的角度解释CsFA PbIBr PSCs晶格结构变化机制的报道却很少。在这项工作中，提出了一种15% Cs阳离子部分取代FA阳离子的简便方法，以提高FAPbIBr PSCs的结构稳定性和光伏性能。Cs在FAPbIBr中的部分掺入导致了更有利的容忍因子，并抑制了元素Pb的深缺陷态。更重要的是，它抑制了FAPbIBr从立方黑色α相到六方黄色δ相的相变。此外，CsFAPbIBr PSCs的功率转换效率（PCE）有了显著提高。稳定性也有了显著提升，这通过X射线光电子能谱（XPS）、X射线衍射（XRD）和核磁共振（NMR）得到了证明。这些分析表明，15% Cs可以诱导晶格收缩，减少特定陷阱并抑制相变，从而提高CsFAPbIBr PSCs在大气和加热条件下的结构稳定性。这些结果为制备具有良好性能的稳定高效无机-有机钙钛矿太阳能电池提供了一条有效途径。
