@article{5a706668c44a4c059df23af9ddf1f772,
title = "Visualizing band alignment across 2D/3D perovskite heterointerfaces of solar cells with light-modulated scanning tunneling microscopy",
abstract = "Graded 2D perovskite capping shells with continuously upshifting valence bands, produced by tailored dimensional engineering, can effectively extract holes from 3D perovskite cores. Real-space observation of electronic structures will fully reveal the operating mechanisms of 2D/3D hybrid perovskite solar cells (PSCs). Here, for the first time, light-modulated scanning tunneling microscopy visualizes the cross-sectional band alignment across 2D (C4H9NH3)2(CH3NH3)n-1PbnI3n+1/3D CH3NH3PbI3 stacked perovskites. By systematically analyzing their electronic configuration, the mixed-dimensional perovskite band structure along the vertical 3D-to-2D direction can be spatially resolved. Remarkably, the electric field in the 2D perovskite is larger under light illumination than under dark conditions, resulting in an increase in the concentration of holes and electrons distributed in the 2D and 3D perovskites, respectively. Benefiting from this electronic reconstruction, charge recombination is suppressed, thereby significantly promoting the 2D/3D PSC performance. Moreover, our method opens an avenue for direct, local mapping of optoelectronic device energy levels.",
keywords = "2D/3D perovskite, Band mapping, Interface, Perovskite solar cells, Scanning tunneling microscopy",
author = "Huang, {Po Cheng} and Huang, {Shao Ku} and Lai, {Ting Chun} and Shih, {Min Chuan} and Hsu, {Hung Chang} and Chen, {Chun Hsiang} and Lin, {Cheng Chieh} and Chiang, {Chun Hao} and Lin, {Chi Ying} and Kazuhito Tsukagoshi and Chen, {Chun Wei} and Chiu, {Ya Ping} and Tsay, {Shiow Fon} and Wang, {Ying Chiao}",
note = "Funding Information: Hung-Chang Hsu received his Ph.D. degree in 2016 from Department of Physics, National Taiwan Normal University. He is currently a postdoctoral researcher at the Department of Physics, National Taiwan University. He received an award of the “Ministry of Science and Technology (MOST) Postdoctoral Researcher Academic Research Award Awardees” in 2019. His research is focus on the interfacial science of the semiconductor and the solar cells. Funding Information: Y.-C.W. acknowledges the financial support from JSPS-KAKENHI (Grant No. 20K15135) and the ICYS, NIMS for the research funds. C.-W.C. acknowledges the financial support from the Ministry of Science and Technology (MOST), Taiwan (Contract No. MOST 108-2923-M-002?002-MY2, MOST-NIMS add-on project). Y.-P.C. acknowledges the financial support from the Ministry of Science and Technology (MOST), Taiwan (Contract No. MOST 109-2628-M-002?005-MY3) and National Taiwan Univ. (Contract No. NTU-109L7848). Financial support provided by the Center of Atomic Initiative for New Materials (AI-Mat), National Taiwan University, from the Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education in Taiwan (Grant No. 108L9008) is also acknowledged. Funding Information: Y.-C.W. acknowledges the financial support from JSPS -KAKENHI (Grant No. 20K15135) and the ICYS, NIMS for the research funds. C.-W.C. acknowledges the financial support from the Ministry of Science and Technology (MOST), Taiwan (Contract No. MOST 108-2923-M-002–002-MY2 , MOST-NIMS add-on project). Y.-P.C. acknowledges the financial support from the Ministry of Science and Technology (MOST), Taiwan (Contract No. MOST 109-2628-M-002–005-MY3 ) and National Taiwan Univ. (Contract No. NTU-109L7848 ). Financial support provided by the Center of Atomic Initiative for New Materials (AI-Mat), National Taiwan University, from the Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education in Taiwan (Grant No. 108L9008 ) is also acknowledged. Publisher Copyright: {\textcopyright} 2021 The Authors",
year = "2021",
month = nov,
doi = "10.1016/j.nanoen.2021.106362",
language = "English",
volume = "89",
journal = "Nano Energy",
issn = "2211-2855",
publisher = "Elsevier BV",
}