Interfacial band offset engineering with barium-doping towards enhanced performance of all inorganic CsPbI2Br perovskite solar cells

Sachin R Rondiya; Sawanta S Mali; Anurag Roy; Gajendra Kumar Inwati; Ganesh K Rahane; Yogesh A Jadhav; Sunil Suresh; Tushar Debnath; Chang Kook Hong; Nelson Y Dzade

doi:10.1039/d3cp02935b

Interfacial band offset engineering with barium-doping towards enhanced performance of all inorganic CsPbI₂Br perovskite solar cells

Phys Chem Chem Phys. 2023 Nov 1;25(42):29050-29060. doi: 10.1039/d3cp02935b.

Authors

Sachin R Rondiya^{1

2}, Sawanta S Mali³, Anurag Roy⁴, Gajendra Kumar Inwati⁵, Ganesh K Rahane², Yogesh A Jadhav⁶, Sunil Suresh⁷, Tushar Debnath⁸, Chang Kook Hong³, Nelson Y Dzade^{1

9}

Affiliations

¹ School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff, CF10 3AT, Wales, UK.
² Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, India. rondiya@iisc.ac.in.
³ Polymer Energy Materials Laboratory, School of Chemical Engineering, Chonnam National University, Gwangju-61186, South Korea. sawanta@jnu.ac.kr.
⁴ Solar Energy Research Group, Faculty of Environment, Science and Economy, Environment & Sustainability Institute, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK.
⁵ Central university of Gujarat, Gandhinagar, 382030, Gujarat, India.
⁶ Symbiosis Center for Nanoscience and Nanotechnology (SCNN), Symbiosis International (Deemed University) (SIU), Lavale, Pune 412115, Maharashtra, India.
⁷ Laboratory for Solar Energy and Fuels (LSEF), School of Engineering, The University of British Columbia Kelowna V1V 1V7, Canada.
⁸ Centre for Nanotechnology, Indian Institute of Technology Guwahati (IIT G), Guwahati, Assam, 781039, India.
⁹ Department of Energy and Mineral Engineering, Pennsylvania State University, University Park, PA 16802, USA. nxd5313@psu.edu.

PMID: 37860862
DOI: 10.1039/d3cp02935b

Abstract

This study investigates the incorporation of Ba²⁺ at a low concentration into CsPbI₂Br, resulting in the formation of mixed CsPb_1-xBa_xI₂Br perovskite films. Photovoltaic devices utilizing these Ba-doped CsPbI₂Br (Ba-CsPbI₂Br) perovskite films achieved a higher stabilized power conversion efficiency of 14.07% compared to 11.60% for pure CsPbI₂Br films. First-principles density functional theory calculations indicate that the improved device performance can be attributed to the efficient transport of conduction electrons across the interface between Ba-CsPbI₂Br and the TiO₂ electron transporting layer (ETL). The Ba-CsPbI₂Br/TiO₂ interface exhibits a type-II staggered band alignment with a smaller conduction band offset (CBO) of 0.25 eV, in contrast to the CsPbI₂Br/TiO₂ interface with a CBO of 0.48 eV. The reduced CBO at the Ba-CsPbI₂Br/TiO₂ interface diminishes the barrier for conduction electrons to transfer from the Ba-CsPbI₂Br layer to the TiO₂ layer, facilitating efficient charge transport.