Effect of structural and temperature variations on perovskite/Mg2Si based monolithic tandem solar cell structure

Abstract

Perovskite being a wide bandgap material has shown profound impact as an active material for the use of top cell in the tandem solar cell. However, finding a suitable low-bandgap material for the bottom cell of the perovskite associated tandem solar cell has always been a concern for researchers. Over the last decade, several materials for designing of the bottom cell have been reported as a combination to perovskite for superior efficiency. In this paper, a novel perovskite/Mg2Si based monolithic tandem solar cell is reported through numerical simulations using AFROS-HET v2.5. The reported device shows 25% efficiency prior to optimization. However, the structure of the device has been optimized to obtain better results in terms of efficiency by varying active layer thickness and using different electron/hole transport materials. About 8% improvement in efficiency has been noticed by the selection of optimum design parameters. Further, to account for the temperature reliability of the proposed design, the device is simulated for a temperature range of 300 K–450 K. This study highlights a drop-in open-circuit voltage (VOC) by a factor of about 0.1 V with an increase in temperature by about 50 K. Results clearly establish that structural and temperature variations significantly affect overall device performance. Results have been suitably analyzed so as to set a roadmap for further research work in this direction and explore the best of the characteristics of this unique tandem solar cell structure.