Passivation Properties and Formation Mechanism of Amorphous Halide Perovskite Thin Films
Passivation Properties and Formation Mechanism of Amorphous Halide Perovskite Thin Films
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DOI：
10.1002/adfm.202010330
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发表时间：
2021-02
影响因子：
19
通讯作者：
Susan A. Rigter;Xueying L. Quinn;Rishi E. Kumar;D. Fenning;P. Massonnet;S. Ellis;R. Heeren;K. Svane;A. Walsh;E. Garnett
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文献类型：
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作者：
Susan A. Rigter;Xueying L. Quinn;Rishi E. Kumar;D. Fenning;P. Massonnet;S. Ellis;R. Heeren;K. Svane;A. Walsh;E. Garnett
卤化铅钙钛矿是最令人兴奋的光电材料之一，因为它们具有使用简单的溶液沉淀反应形成可见光和近红外波段带隙可调的高质量晶体的独特能力。这种容易的结晶是由它们的离子性质驱动的。与其他盐一样，形成无定形卤化物钙钛矿具有挑战性，尤其是最容易研究的薄膜形式。在这里，通过添加乙酸盐前体促进快速去溶剂化被证明是制备具有多种成分的非晶卤化铅钙钛矿薄膜的通用方法，包括使用常见有机阳离子（甲基铵和甲脒）和阴离子（溴化物和碘化物）的那些。通过控制醋酸盐的量，可以从完全结晶薄膜调整到完全非晶薄膜，并具有由嵌入非晶基质中的结晶岛组成的有趣的中间态。非晶卤化铅钙钛矿具有大且可调的光学带隙。它提高了掺入的晶体钙钛矿的光致发光量子产率和寿命，开启了使用非晶钙钛矿作为钝化接触的有趣可能性，正如目前在创纪录效率的硅太阳能电池中所做的那样。
Lead halide perovskites are among the most exciting classes of optoelectronic materials due to their unique ability to form high‐quality crystals with tunable bandgaps in the visible and near‐infrared using simple solution precipitation reactions. This facile crystallization is driven by their ionic nature; just as with other salts, it is challenging to form amorphous halide perovskites, particularly in thin‐film form where they can most easily be studied. Here, rapid desolvation promoted by the addition of acetate precursors is shown as a general method for making amorphous lead halide perovskite films with a wide variety of compositions, including those using common organic cations (methylammonium and formamidinium) and anions (bromide and iodide). By controlling the amount of acetate, it is possible to tune from fully crystalline to fully amorphous films, with an interesting intermediate state consisting of crystalline islands embedded in an amorphous matrix. The amorphous lead halide perovskite has a large and tunable optical bandgap. It improves the photoluminescence quantum yield and lifetime of incorporated crystalline perovskite, opening up the intriguing possibility of using amorphous perovskite as a passivating contact, as is currently done in record efficiency silicon solar cells.