Lead-Free Perovskite Homojunction-Based HTM-Free Perovskite Solar Cells: Theoretical and Experimental Viewpoints

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Date
2023-03-08
Authors
Sajid, Sajid
Alzahmi, Salem
Salem, Imen Ben
Park, Jongee
Obaidat, Ihab M.
Journal Title
Journal ISSN
Volume Title
Publisher
Nanomaterials
Abstract
Simplifying the design of lead-free perovskite solar cells (PSCs) has drawn a lot of interest due to their low manufacturing cost and relative non-toxic nature. Focus has been placed mostly on reducing the toxic lead element and eliminating the requirement for expensive hole transport materials (HTMs). However, in terms of power conversion efficiency (PCE), the PSCs using all charge transport materials surpass the environmentally beneficial HTM-free PSCs. The low PCEs of the lead-free HTM-free PSCs could be linked to poorer hole transport and extraction as well as lower light harvesting. In this context, a lead-free perovskite homojunction-based HTM-free PSC was investigated, and the performance was then assessed using a Solar Cell Capacitance Simulator (SCAPS). A two-step method was employed to fabricate lead-free perovskite homojunction-based HTM-free PSCs in order to validate the simulation results. The simulation results show that high hole mobility and a narrow band gap of cesium tin iodide (CsSnI3) boosted the hole collection and absorption spectrum, respectively. Additionally, the homojunction’s built-in electric field, which was identified using SCAPS simulations, promoted the directed transport of the photo-induced charges, lowering carrier recombination losses. Homojunction-based HTM-free PSCs having a CsSnI3 layer with a thickness of 100 nm, defect density of 1015 cm−3, and interface defect density of 1018 cm−3 were found to be capable of delivering high PCEs under a working temperature of 300 K. When compared to formamidinium tin iodide (FASnI3)-based devices, the open-circuit voltage (Voc), short-circuit density (Jsc), fill factor (FF), and PCE of FASnI3/CsSnI3 homojunction-based HTM-free PSCs were all improved from 0.66 to 0.78 V, 26.07 to 27.65 mA cm−2, 76.37 to 79.74%, and 14.62 to 19.03%, respectively. In comparison to a FASnI3-based device (PCE = 8.94%), an experimentally fabricated device using homojunction of FASnI3/CsSnI3 performs better with Voc of 0.84 V, Jsc of 22.06 mA cm−2, FF of 63.50%, and PCE of 11.77%. Moreover, FASnI3/CsSnI3-based PSC is more stable over time than its FASnI3-based counterpart, preserving 89% of its initial PCE. These findings provide promising guidelines for developing highly efficient and environmentally friendly HTM-free PSCs based on perovskite homojunction.
Description
Open Access, Published by Nanomaterials, https://doi.org/10.3390/nano13060983, Sajid Sajid, Salem Alzahmi, Department of Chemical & Petroleum Engineering, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates, National Water and Energy Center, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates, Imen Ben Salem, College of Natural and Health Sciences, Zayed University, Abu Dhabi P.O. Box 144534, United Arab Emirates, Jongee Park, Department of Metallurgical and Materials Engineering, Atilim University, Ankara 06836, Turkey, Ihab M. Obaidat, National Water and Energy Center, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates, Department of Physics, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates.
Keywords
Lead-free; HTM-free PSC; high efficiency; simulation; experiment
Citation
http://hdl.handle.net/20.500.14411/1898