Interfacial Sulfur Functionalization Anchoring SnO2 and CH3NH3PbI3 for Enhanced Stability and Trap Passivation in Perovskite Solar Cells. Issue 22 (2nd November 2018)

• Record Type: Journal Article
• Authors: Wang, Zhen; Kamarudin, Muhammad Akmal; Huey, Ng Chi; Yang, Fu; Pandey, Manish; Kapil, Gaurav; Ma, Tingli; Hayase, Shuzi
• Is Part Of: ChemSusChem. Volume 11:Issue 22(2018)
• Page Start: 3941
• Page End: 3948
• Publication Date: 2018-11-02
• Subjects: interfacial engineering -- perovskites -- solar cells -- sulfur -- trap passivation; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201801888
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: Trap states at the interface or in bulk perovskite materials critically influence perovskite solar cells performance and long‐term stability. Here, a strategy for efficiently passivating charge traps and mitigating interfacial recombination by SnO2 surface sulfur functionalization is reported, which utilizes xanthate decomposition on the SnO2 surface at low temperature. The results show that functionalized sulfur atoms can coordinate with under‐coordinated Pb 2+ ions near the interface. After device fabrication under more than 60 % humidity in ambient air, the efficiency of methylammonium lead iodide (MAPbI3 ) perovskite solar cells based on sulfur‐functionalized SnO2 increased from 16.56 % to 18.41 % with suppressed hysteresis, which resulted from the accelerated interfacial charge transport kinetics and decreased traps in bulk perovskite by interfacial sulfur functionalization. Additionally, thermally stimulated current studies show the decreased trap density in the shallow trap area after interfacial sulfur functionalization. The interfacial sulfur functionalized solar cells without sealing also exhibited considerable retardation of solar cell degradation with only 10 % degradation after 70 days air storage. This work demonstrates a facile sulfur functionalization strategy by using xanthate decomposition on SnO2 surfaces to obtain highly efficient perovskite solar cells. Abstract : Inorganic sulfur functionalization has been realized through xanthate annealing on a SnO2 substrate, facilitating electron transport and reducing trap density at the shallow area. The efficiency of the resulting perovskite device was increased significantly with enhanced long‐term stability upon interfacial sulfur functionalization. This method is a simple and highly efficient means of interfacial functionalization with enhanced stability by using inorganic atoms.