Nanoscale control of grain boundary potential barrier, dopant density and filled trap state density for higher efficiency perovskite solar cells
Behzad Bahrami,
Sally Mabrouk,
Nirmal Adhikari,
Hytham Elbohy,
Ashim Gurung,
Khan M. Reza,
Rajesh Pathak,
Ashraful H. Chowdhury,
Gopalan Saianand,
Wenjin Yue,
Jiantao Zai,
Xuefeng Qian,
Mao Liang,
Qiquan Qiao
Affiliations
Behzad Bahrami
Department of Electrical Engineering and Computer Science, Center for Advanced Photovoltaics and Sustainable Energy South Dakota State University Brookings South Dakota
Sally Mabrouk
Department of Electrical Engineering and Computer Science, Center for Advanced Photovoltaics and Sustainable Energy South Dakota State University Brookings South Dakota
Nirmal Adhikari
Department of Electrical Engineering and Computer Science, Center for Advanced Photovoltaics and Sustainable Energy South Dakota State University Brookings South Dakota
Hytham Elbohy
Physics Department Damietta University New Damietta City Egypt
Ashim Gurung
Department of Electrical Engineering and Computer Science, Center for Advanced Photovoltaics and Sustainable Energy South Dakota State University Brookings South Dakota
Khan M. Reza
Department of Electrical Engineering and Computer Science, Center for Advanced Photovoltaics and Sustainable Energy South Dakota State University Brookings South Dakota
Rajesh Pathak
Department of Electrical Engineering and Computer Science, Center for Advanced Photovoltaics and Sustainable Energy South Dakota State University Brookings South Dakota
Ashraful H. Chowdhury
Department of Electrical Engineering and Computer Science, Center for Advanced Photovoltaics and Sustainable Energy South Dakota State University Brookings South Dakota
Gopalan Saianand
Global Innovative Center for Advanced Nanomaterials, Faculty of Engineering The University of Newcastle Callaghan New South Wales Australia
Wenjin Yue
College of Biochemical Engineering Anhui Polytechnic University Wuhu China
Jiantao Zai
Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Shanghai China
Xuefeng Qian
Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Shanghai China
Mao Liang
Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Department of Applied Chemistry Tianjin University of Technology Tianjin China
Qiquan Qiao
Department of Electrical Engineering and Computer Science, Center for Advanced Photovoltaics and Sustainable Energy South Dakota State University Brookings South Dakota
Abstract In this work, grain boundary (GB) potential barrier ( Δφ GB), dopant density (Pnet), and filled trap state density (PGB,trap) were manipulated at the nanoscale by exposing the fabricated perovskite films to various relative humidity (RH) environments. Spatial mapping of surface potential in the perovskite film revealed higher positive potential at GBs than inside the grains. The average Δφ GB, Pnet, and PGB,trap in the perovskite films decreased from 0% RH to 25% RH exposure, but increased when the RH increased to 35% RH and 45% RH. This clearly indicated that perovskite solar cells fabricated at 25% RH led to the lowest average GB potential, smallest dopant density, and least filled trap states density. This is consistent with the highest photovoltaic efficiency of 18.16% at 25% RH among the different relative humidities from 0% to 45% RH.
