To promote commercialization of perovskite solar cells (PSCs), low-temperatureprocessed electron transport layer (ETL) with high carrier mobility still needs tobe further developed. Here, we reported two-dimensional (2D) tin disulfide(SnS2) nanosheets as ETL in PSCs for the first time. The morphologies of the 2DSnS2 material can be easy controlled by the in situ synthesized method on theconductive fluorine-doped fin oxide (FTO) substrate. We achieved a championpower conversion efficiency (PCE) of 13.63%, with the short-circuit currentdensity (Jsc) of 23.70 mA/cm2 open-circuit voltage (Voc) of 0.95 V, and fill factor(FF) of 0.61. The high Jsc of PSCs results from effective electron collection ofthe 2D SnS2 nanosheets from perovskite layer and fast electron transport tothe FTO. The low Voc and FF are the results of the lower conduction band of 2DSnS2 (4.23 eV) than that of TiO2 (4.0 eV). These results demonstrate that 2Dmaterial is a promising candidate for ETL in PSCs.
Erling ZhaoLiguo GaoShuzhang YangLikun WangJunmei CaoTingli Ma
随着社会工业化的发展,环境污染问题日益严重,控制与治理环境污染已经成为人类社会亟待解决的重大科学问题。在众多治理方法中,半导体光催化材料以其独特的性能成为一种理想的环境污染治理清洁材料,主要应用于降解有毒物质、光催化分解水和光电转化等方面。二氧化钛(TiO_2)作为一种应用广泛的宽带隙半导体光催化材料,因其催化活性高、化学稳定性好、对人体无毒害、成本低廉等优点,被认为是最重要的光催化剂之一。然而,TiO_2的禁带宽度较宽(3.2 e V),对光的利用率较低,只能吸收波长较短的紫外光,直接制约着TiO_2的应用。围绕如何拓宽TiO_2的光谱吸收范围,从化学和物理两个方面对近年来实现TiO_2可见光光催化的途径和方法进行了简要总结。化学方面主要对表面光敏化、元素掺杂进行总结,物理方面主要对慢光效应、米氏散射效应及表面等离子体共振进行综述。此外,还在深入理解现有TiO_2可见光体系的光催化机理,发现更高效的体相掺杂剂和表面敏化剂,设计和控制掺杂剂和表面敏化剂存在形态,进一步提高TiO_2光催化效率等方面做了展望。