Air-stable bismuth sulfobromide (BiSBr) visible-light absorbers: optoelectronic properties and potential for energy harvesting
Air-stable bismuth sulfobromide (BiSBr) visible-light absorbers: optoelectronic properties and potential for energy harvesting
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空气稳定的磺溴化铋 (BiSBr) 可见光吸收剂：光电特性和能量收集潜力
DOI：
10.1039/d3ta04491b
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发表时间：
2023
影响因子：
11.9
通讯作者：
Guo X
中科院分区：
文献类型：
--
作者：
Guo X
NS 2化合物最近由于其复制铅卤化物钙钛矿的缺陷容限并克服其毒性和稳定性限制的潜力而吸引了相当大的兴趣。然而，到目前为止，只有少数钙钛矿家族以外的化合物被探索过。在这里，我们研究了磺溴化铋（BiSBr），这是一种准一维半导体，但很少有人知道它的光电性能或如何可以处理成薄膜。我们开发了一种溶液处理路线，以实现相纯，化学计量比BiSBr薄膜（约。240 nm厚），我们显示其在环境空气中稳定超过两周而不包封。带隙（1.91 ± 0.06 eV）对于从普通室内光源收集可见光是理想的，并且我们计算了效率的光学极限（即，光谱极限最大效率，SLME）在1000勒克斯白色发光二极管照明下为43.6%。光致发光寿命也被发现超过1 ns的阈值，值得进一步发展的光伏吸收材料。通过X射线光电子能谱和Kelvin探针测量，我们发现BiSBr薄膜为n型，电子亲和势为4.1 ± 0.1 eV，电离势为6.0 ± 0.1 eV，与广泛的电荷传输层材料兼容。这项工作表明，BiSBr有望用于室内光电转换，以及其他可见光收集应用，如光电化学电池或串联光电转换的顶电池。
ns2 compounds have recently attracted considerable interest due to their potential to replicate the defect tolerance of lead-halide perovskites and overcome their toxicity and stability limitations. However, only a handful of compounds beyond the perovskite family have been explored thus far. Herein, we investigate bismuth sulfobromide (BiSBr), which is a quasi-one-dimensional semiconductor, but very little is known about its optoelectronic properties or how it can be processed as thin films. We develop a solution processing route to achieve phase-pure, stoichiometric BiSBr films (ca. 240 nm thick), which we show to be stable in ambient air for over two weeks without encapsulation. The bandgap (1.91 ± 0.06 eV) is ideal for harvesting visible light from common indoor light sources, and we calculate the optical limit in efficiency (i.e., spectroscopic limited maximum efficiency, SLME) to be 43.6% under 1000 lux white light emitting diode illumination. The photoluminescence lifetime is also found to exceed the 1 ns threshold for photovoltaic absorber materials worth further development. Through X-ray photoemission spectroscopy and Kelvin probe measurements, we find the BiSBr films grown to be n-type, with an electron affinity of 4.1 ± 0.1 eV and ionization potential of 6.0 ± 0.1 eV, which are compatible with a wide range of established charge transport layer materials. This work shows BiSBr to hold promise for indoor photovoltaics, as well as other visible-light harvesting applications, such as photoelectrochemical cells, or top-cells for tandem photovoltaics.