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Developed through bandgap engineering and materials design, the proposed photovoltaic device is based on a tin-based perovskite material known as CsSnI3-xBrx. Apparently it can be designed to achieve power conversion efficiencies greater than 24%.
Researchers at Chiktara University (India) claim to have improved the stability and performance of organic-inorganic perovskite solar cells by applying a strategy called bandgap grading.
It consists of enabling the cells perovskite absorber to collect a broader range of light photons by modifying its thickness and characteristics. “Our study demonstrates the effectiveness of linear and parabolic bandgap grading strategies to optimize light absorption and increase performance,” Jaya Madan, lead author of the research, told pv magazine . “Parabolic gradation is especially promising.”
The scientists used the SCAPS-1D solar cell capacitance software, developed by Ghent University, to simulate the novel cell configuration. They hypothesized that the cell was based on a lead-free, tin-based perovskite material known as CsSnI3-xBrx. “Incorporating bandgap tailoring results in bandgap/affinity modulation along the depth of the absorbing layer, which increases the efficiency of the solar cell,” they explained.
The cell was initially designed with a fluorine-doped tin oxide (FTO) substrate, an electron transport layer (ETL) of ceric oxide (CeO2), the perovskite absorber, a hole transport layer (HTL) of copper, iron and tin (Cu2FeSnS4) and a gold (Au) metal contact.
For both the ETL and the HTL, a thickness of 100 nm was assumed, while for the absorber the academics considered a thickness ranging between 50 nm and 500 MW, with a variable bandgap energy between 1.25 eV and 1. 78 eV.
Tested under standard lighting conditions, the proposed solar cell configuration achieved a power conversion efficiency of 23.61% with the parabolic gradation approach and 21.68% with linear gradation. The simulations also showed that by replacing the ETL and HTL materials used with tin oxide (SnO2) and PEDOT:PSS, respectively, the cell efficiency can also exceed 24%.
The new solar cell concept is described in the study “ Maximizing photovoltaic performance of all- inorganic perovskite CsSnI3-xBrx solar cells through bandgap grading and material design.” bandgap and materials design), published in Solar Energy .
“Our research presents a compelling route to achieving high-performance, sustainable and stable perovskite solar cells,” concludes Madan. “The advances in bandgap engineering and materials design presented in this study hold great promise for accelerating the commercialization of lead-free perovskite photovoltaic technologies.” |
