Intermittent sulfurization-a method promoting Macro-Porous Cu-Poor Zn-Rich-kesterite CZTS as HTM for inverted perovskite solar cell application

摘要

Porous semiconductors have emerged as a lucrative apparatus for energy-harvesting applications with more exceptional ability as compared to their bulk counterpart. Exposure of a new porous formation strategy for the abundant semiconductor CZTS could initiate an extensive exploration for solar cell applications. Available porous formation strategies for the CZTS have neglected a significant factor of its compositional balance, which needs to be assisted carefully. In this work, intermittent sulfurization technique is used to promote macro-porous CZTS towards perovskite solar cell applications. This technique not only promotes the macro-porosity of CZTS but also successfully controls its compositional balance to fulfill the favorable Cu-poor Zn-rich condition. Every tuned step of this technique causes a different morphology and composition, which has been investigated by FESEM and EDX mapping. Meanwhile, characterization of phase, crystallinity, and optical bandgap have also been investigated by XRD, Raman spectroscopy, and UV-Vis spectroscopy, respectively, for the resulted in macro-porous Kesterite CZTS. Inverted (p-i-n)-structured perovskite solar cell with p-type macro-porous CZTS as hole transporter material delivered 3.33% power conversion efficiency. Synthesis of perovskite material and electron transporting material along with the fabrication of (p-i-n)-structured perovskite solar cells have also been detailed here.