대표연구 논문 실적
Nanoscale Mapping of Charge-Trap-Induced Localized Bandgap Variations in Perovskite Solar Cell Structures via Wavelength-Depend
발행년도
20251006
저자
Mingyu Jung, Alan Jiwan Yun, Yuhyeon Oh, Shashank Shekhar, Byungwoo Park, Seunghun Hong
저널
ACS Applied Materials & Interfaces
작성자
전지현
작성일
2025-10-16
조회
20
ABSTRACT
We report the nanoscale mapping of charge-trapinduced local bandgap variations in an organic−inorganic halide perovskite film within a solar cell structure. For mapping, a conducting probe scanned the perovskite film surface under monochromatic illumination at different wavelengths to simultaneously map wavelength-dependent photocurrents and electrical noise. The measured maps were analyzed further to obtain the spatial distributions of photoconductive properties, such as photocurrent (I pc ), short-circuit current (I sc ), and charge trap density (N eff ), in the film. Interestingly, both the photocurrent and short-circuit current exhibited negative correlations with trap density following distinct power-law relationships. Importantly, a local bandgap (E g ) map was obtained from wavelength-dependent photocurrent maps by applying the Tauc plot method with local external quantum efficiencies (EQE) at different wavelengths, revealing spatial variations across the perovskite film. Quantitative analysis revealed a correlation between variations of bandgap and effective trap density following ΔE g ∝ N eff
direct mapping of nanoscale photoconductive properties and their quantitative correlations, providing a powerful tool for both fundamental research and practical applications in optoelectronic devices.
https://doi.org/10.1021/acsami.5c15108
We report the nanoscale mapping of charge-trapinduced local bandgap variations in an organic−inorganic halide perovskite film within a solar cell structure. For mapping, a conducting probe scanned the perovskite film surface under monochromatic illumination at different wavelengths to simultaneously map wavelength-dependent photocurrents and electrical noise. The measured maps were analyzed further to obtain the spatial distributions of photoconductive properties, such as photocurrent (I pc ), short-circuit current (I sc ), and charge trap density (N eff ), in the film. Interestingly, both the photocurrent and short-circuit current exhibited negative correlations with trap density following distinct power-law relationships. Importantly, a local bandgap (E g ) map was obtained from wavelength-dependent photocurrent maps by applying the Tauc plot method with local external quantum efficiencies (EQE) at different wavelengths, revealing spatial variations across the perovskite film. Quantitative analysis revealed a correlation between variations of bandgap and effective trap density following ΔE g ∝ N eff
direct mapping of nanoscale photoconductive properties and their quantitative correlations, providing a powerful tool for both fundamental research and practical applications in optoelectronic devices.
https://doi.org/10.1021/acsami.5c15108
