双功能NH4F添加剂辅助水热法沉积制备高性能Sb_(2)(S,Se)_(3)用于太阳能电池

Dual effect of NH4F additive in the hydrothermal deposition of antimony selenosulfide thin film for high-performance solar cells

基于水热法硒硫化锑(Sb_(2)(S,Se)_(3))的太阳能电池的光电效率已经突破10%.但是,在沉积过程中使用的锑、硫和硒前驱物之间的反应会使Sb_(2)(S,Se)_(3)薄膜内部产生不利的Se和S阴离子梯度,限制效率的进一步提升.本文中我们利用NH_(4)F作为一种添加剂来调节Sb_(2)(S,Se)_(3)薄膜的能级梯度,并修饰CdS电子传输层表面.一方面,NH_(4)F可以抑制硫代硫酸钠(Na_(2)S_(2)O_(3))和硒脲的释放速度,调节Se/S在Sb_(2)(S,Se)_(3)薄膜中的比例和分布;另一方面,NH_(4)F的水解诱导CdS的溶解和再沉积,有效地改善CdS衬底的形貌和结晶度.最后,在NH_(4)F的双重作用下,Sb_(2)(S,Se)_(3)薄膜的形貌得到改善,并且能量取向良好,效率最高达到10.28%,相比无NH_(4)F的器件提高了12%.本研究可以为改善硫化物衬底和硫族化合物薄膜提供一种有效的策略,并使其用于光电器件.

Hydrothermal deposition of antimony selenosulfide(Sb_(2)(S,Se_(3)))has enabled solar cell applications to surpass the 10%efficiency threshold.This deposition process involves the reaction of three precursor materials:Sb,S,and Se.However,this process generates an unfavourable gradient of Se and S anions in the Sb_(2)(S,Se)_(3)film,which limits further efficiency improvements.Herein,we demonstrate how NH_(4)F can be used as an additive to regulate the band gradient of the Sb_(2)(S,Se)_(3)and modify the surface of the CdS electron-transporting layer.On the one hand,NH_(4)F inhibits the decomposition of Na_(2)S_(2)O_(3)and selenourea,which optimizes the deposition process and allows for adjustment of the Se/S ratio and their distribution in the Sb_(2)(S,Se)_(3)film.On the other hand,hydrolysis of NH_(4)F induces dissolution and redeposition of CdS,thereby effectively improving the morphology and crystallinity of the CdS substrate.Finally,the dual effect of NH_(4)F enables improved surface morphology and energy alignment of the Sb_(2)(S,Se)_(3)film,thus yielding a maximum efficiency of 10.28%,a 12%improvement over the control device.This study demonstrates an effective strategy for simultaneously modifying a sulfide-based substrate and regulating the element distribution during the deposition of a metal chalcogenide film for optoelectronic device applications.