Comparison of thermal behaviors of silicon and perovskite solar cells through coupled optical-electrical-thermal 3-D modeling using COMSOL

Abstract

In this thesis, we presented a comparative and comprehensive analysis of heat generation and dissipation in a typical perovskite solar cell and an amorphous silicon (a-Si) solar cell through a coupled optical-electrical-thermal 3D simulation strategy using COMSOL Multiphysics. In order to thoroughly investigate the major heat generation and transfer mechanisms in both types of solar cells, the major challenge we have tackled is to integrate the analysis from the heat transfer module with that from the wave-optics and semiconductor modules in 3D. As a preliminary step in developing such an analysis scheme, our study here focused on three significant heat loss mechanisms in solar cells: thermalization, non-radiative recombination, and joule heating. For the comparison of heat exchange with the surrounding environment of the two cells, we looked into conduction and convection heat transfer boundary conditions combined with the thermal properties of each individual cell. The non-trivial heat loss contributions from non-radiative recombination in both solar cells were analyzed, which highlighted the impact of defective states within the bandgap. The analysis of joule heating led to the illustration of the effect of high electric fields at the junctions. In our findings, the perovskite and a-Si solar cells exhibit very distinct optical, electrical, and thermal behaviors owing to their respective material properties and device structures. The results indicate correlations between a certain heat loss mechanism and cell structural and material properties. This modeling strategy is helpful in the heat performance evaluation of the two important types of solar cells and provides meaningful guidance on designing high-efficiency solar cells and even recycling of heat losses from the aspects of material selection, dominant heat loss mechanisms, and heat exchange effectiveness with the surrounding environment.