Lim Jihoo, Choi Eunyoung, Kim Moonyong, Lee Minwoo, Chen Daniel, Green Martin A, Seidel Jan, Kim Changheon, Park Jongsung, Hao Xiaojing, Yun Jae Sung
Australian Centre for Advanced Photovoltaics (ACAP), School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney, NSW 2052, Australia.
School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia.
ACS Appl Mater Interfaces. 2022 May 11;14(18):20866-20874. doi: 10.1021/acsami.2c01061. Epub 2022 May 2.
Copper (Cu) is present not only in the electrode for inverted-structure halide perovskite solar cells (PSCs) but also in transport layers such as copper iodide (CuI), copper thiocyanate (CuSCN), and copper phthalocyanine (CuPc) alternatives to spiro-OMeTAD due to their improved thermal stability. While Cu or Cu-incorporated materials have been effectively utilized in halide perovskites, there is a lack of thorough investigation on the direct reaction between Cu and a perovskite under thermal stress. In this study, we investigated the thermal reaction between Cu and a perovskite as well as the degradation mechanism by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Kelvin probe force microscopy (KPFM). The results show that high temperatures of 100 °C induce Cu to be incorporated into the perovskite lattice by forming "Cu-rich yet organic A-site-poor" perovskites, (CuA)PbX, near the grain boundaries, which result in device performance degradation.
铜（Cu）不仅存在于倒置结构卤化物钙钛矿太阳能电池（PSC）的电极中，还存在于诸如碘化铜（CuI）、硫氰酸铜（CuSCN）和铜酞菁（CuPc）等传输层中，这些是螺环-OMeTAD的替代品，因为它们具有更高的热稳定性。虽然铜或含铜材料已在卤化物钙钛矿中得到有效利用，但对于铜与钙钛矿在热应力下的直接反应缺乏深入研究。在本研究中，我们通过X射线衍射（XRD）、X射线光电子能谱（XPS）和开尔文探针力显微镜（KPFM）研究了铜与钙钛矿之间的热反应以及降解机制。结果表明，100°C的高温会促使铜通过在晶界附近形成“富铜但贫有机A位”的钙钛矿（CuA）PbX掺入钙钛矿晶格中，从而导致器件性能下降。
