Thermal modeling of perovskite solar cells: Electron and hole transfer layers effects

Abstract

The thermal behavior of perovskite solar cells (PSCs) can significantly affect their performance, and its investigation leads to a deep understanding of PSCs optimization. In this paper, the electrical and thermal behavior of a PSC is studied. To this end, the optical generation rate is calculated for the standard AM 1.5 solar spectrum and then is applied to calculate the current-voltage characteristics. Examining the efficiency (considering the recombination) for different materials of the electron and hole transfer layers (ETM, HTM, respectively), a structure with better merits is selected. The results revealed that Spiro-OMeTAD as the HTM layer leads to better results than the inorganic one. Hence, the Spiro-OMeTAD-based PSC structures were selected for the thermal modeling section. In the final step, considering the heat generated due to losses (resulting from resistive heating and non-radiative recombination), the thermal behavior of devices is surveyed. The structures with geometrical dimensions of a practical PSC (deposited on a glass substrate with a SiO2 passivation layer) show operating temperatures between 73 °C to 76°C and 80°C to 84.5°C for ZnO and TiO2 as ETMs, respectively. The high heat generated in the perovskite layer can accelerate its undesirable chemical reactions. Surveying the temperature distribution of PSCs can pave the way to study its effects on ion migration and the corrosion of contacts, which are the main drawbacks of such low-cost energy harvesters.