Research Projects

In recent years, a novel class of solar cells based on hybrid perovskite materials with the highest reported power conversion efficiency (PCE) of ~24.4% attracted potential research interest in order to obtain higher energy conversion efficiency at considerably lower processing costs. There have been several reports on various kinds of perovskite solar cells featuring numerous fabrication schemes and device concepts having augmented photovoltaic performance. Although for a single junction solar cell the power conversion efficiency is limited by Schockley-Quiesser limit, multi-junction solar cells can surpass this limit through collection of solar energy from a large portion of the solar spectrum. In this regard perovskite materials with compositional variations are well suited since they exhibit tunable bandgap ranging 1.18-2.3 eV obtained by varying composition of the cation in their crystal structure. In addition, such materials offer high absorption coefficient, attractive carrier mobility and large diffusion length of carriers. To further improve PCE of solar cells an efficient technique could be to construct solar cells that comprise multi-junction perovskite layers featuring different energy gaps so as to capture a broad portion of the solar spectrum. A myriad of such multi-junction structures could be possible, giving rise to a challenge between performance optimization and design complexity. In this project, a large number of promising and fabrication-feasible multi-junction solar cells using different perovskite materials will be designed, analyzed and optimized for maximizing power conversion efficiency while reducing design complexity. In particular, emphasis will be given on the two-terminal three-junction perovskite materials having suitably chosen energy gaps to capture nearly the entire solar spectrum alongside optimization of thickness of the absorber layers while matching the short-circuit current density. Furthermore, in order to avoid toxicity of lead based perovskite absorbers, the current project is focused on design, analysis and optimization of multi-junction solar cells using eco-friendly perovskite materials using tin.

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