Substrate dependence on (Sb4Se6)(n) ribbon orientations of antimony selenide thin films: Morphology, carrier transport and photovoltaic performance
Substrate dependence on (Sb4Se6)(n) ribbon orientations of antimony selenide thin films: Morphology, carrier transport and photovoltaic performance
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硒化锑薄膜 (Sb4Se6)(n) 带方向的基底依赖性：形态、载流子传输和光伏性能
DOI：
10.1016/j.jallcom.2021.158703
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发表时间：
2021
影响因子：
6.2
通讯作者：
Pang Jinbo
中科院分区：
文献类型：
--
作者：
Zhou Jing;Chen Hanbo;Zhang Xintong;Chi Kailin;Cai Yongmao;Cao Yu;Pang Jinbo
近年来，硒化锑（Sb2Se3）作为薄膜太阳能电池的光活性材料显示出巨大的潜力。为了了解具有一维晶体结构的Sb2Se3薄膜的生长机制和载流子输运行为，系统地表征了具有不同择优取向的Sb2Se3薄膜的结构、性能和光伏性能。结果表明，Sb2Se3薄膜的微观结构主要由(Sb4Se6)n带的横向和纵向竞争生长决定。随着(Sb4Se6)n带的横向生长比例越来越大，薄膜表面更加平坦，微观结构更加致密，但垂直载流子传输能力相应减弱。相反，当(Sb4Se6)n带以垂直生长模式为主时，Sb2Se3薄膜倾向于形成排列的纳米棒结构。该结构具有优异的垂直载流子传输能力；然而，由于丰富的晶界，这也不可避免地导致载流子复合增加。随着Sb2Se3薄膜的沉积逐渐从横向生长转变为垂直生长，由于载流子传输的增强，太阳能电池的性能得到改善。然而，当垂直生长率过高时，器件的填充因子会因漏电流的增加而降低。我们证明，调节 Sb2Se3 光活性层的横向和垂直生长比例对于生产高效太阳能电池至关重要。
In recent years, antimony selenide (Sb2Se3) has shown great potential as a photoactive material for thin film solar cells. To understand the growth mechanism and carrier transport behavior of Sb2Se3thin films with the 1D crystal structure, the structure, properties, and photovoltaic performance of Sb2Se3thin films with different preferred orientations were systematically characterized. The results show that Sb2Se3thin films’ microstructure is mainly determined by the competing lateral and vertical growth of (Sb4Se6)nribbons. As the (Sb4Se6)nribbons’ lateral growth proportion becomes more significant, the thin film gets a flatter surface and denser microstructure, but the vertical carrier transport capability is correspondingly weaker. In contrast, when (Sb4Se6)nribbons are dominated by the vertical growth mode, Sb2Se3thin films tend to form an arranged nanorods structure. This structure has excellent vertical carrier transport capability; however, it also inevitably leads to increased carrier recombination due to the abundant grain boundary. As the deposition of the Sb2Se3thin film gradually changes from the lateral growth to the vertical growth, the solar cell performance could be improved due to the enhancement of carrier transport. However, when the vertical growth ratio is too high, the fill factor of the device will reduce due to the increase of the leakage current. We demonstrate that the regulation of lateral and vertical growth proportion in Sb2Se3photoactive layers is essential to yielding an efficient solar cell.