A Versatile Thin-Film Deposition Method for Multidimensional Semiconducting Bismuth Halides
A Versatile Thin-Film Deposition Method for Multidimensional Semiconducting Bismuth Halides
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DOI：
10.1021/acs.chemmater.8b01341
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发表时间：
2018-05-22
影响因子：
8.6
通讯作者：
Mitzi, David B.
中科院分区：
文献类型：
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作者：
Khazaee, Maryam;Sardashti, Kasra;Mitzi, David B.
尽管在制造有机-无机卤化铅钙钛矿混合太阳能电池方面取得了重大进展，但其毒性和低稳定性仍然是主要缺点，从而阻碍了大规模商业化。考虑到铅（II）和铋（III）离子的等电子性质，可能会在铋基卤化物半导体中找到薄膜光伏（PV）器件中高效光吸收的潜在稳定且无毒的替代品。然而，许多这些系统的高质量多晶薄膜尚未被证明。在这里，我们提出了一种通用和简单的两步共蒸发方法来制备a (3)Bi(2)I(9) （a = Cs, Rb）和AgBi2I7多晶薄膜，具有光滑，无针孔的形貌，平均晶粒尺寸为>200 nm。该工艺包括一个初始的双源蒸发步骤（包括CsI、RbI或AgI和BiI3源），然后是BiI3蒸汽下的退火步骤。通过x射线衍射、光谱学、x射线/紫外光电子能谱和扫描电子显微镜研究所得薄膜的结构、光学和电学特性。
Despite the significant progress in fabricating hybrid organic-inorganic lead halide perovskite solar cells, their toxicity and low stability remain as major drawbacks, thereby hindering large-scale commercialization. Given the isoelectronic nature of lead(II) and bismuth(III) ions, potentially stable and nontoxic alternatives for efficient light absorption in thin-film photovoltaic (PV) devices may be found among bismuth-based halide semiconductors. However, high-quality polycrystalline films of many of these systems have not been demonstrated. Here we present a versatile and facile two-step coevaporation approach to fabricate A(3)Bi(2)I(9) (A = Cs, Rb) and AgBi2I7 polycrystalline films with smooth, pinhole-free morphology and average grain size of >200 nm. The process involves an initial two-source evaporation step (involving CsI, RbI or AgI, and BiI3 sources), followed by an annealing step under BiI3 vapor. The structural, optical, and electrical characteristics of the resulting thin films are studied by X-ray diffraction, optical spectroscopy, X-ray/UV photoelectron spectroscopy, and scanning electron microscopy.