CROSS-INFLUENCE OF TEMPERATURE AND FRONT LAYER THICKNESS ON THE PERFORMANCE OF A HETEROJUNCTION SOLAR CELL

This study investigates the combined influence of temperature and the thickness of the front surface field (FSF) layer on the electrical performance of a heterojunction solar cell with the structure [(p)-a-Si:H/(n)c Si/(n) aSi:H]. The analysis is based on numerical simulations performed using the Atlas module of the TCAD SILVACO suite, considering a temperature range from 275 K to 330 K and FSF layer thicknesses varying between 2 nm and 20 nm.The simulation results reveal a simultaneous degradation of both the open circuit voltage (V_oc) and the short circuit current density (J_sc) as the temperature increases, particularly in the intermediate FSF thickness range of 3 10 nm. This behavior is primarily attributed to the enhanced carrier recombination at elevated temperatures, especially when the FSF layer is too thin to ensure effective field-induced passivation.In contrast, thicker FSF layers, specifically those ranging from 13 nm to 20 nm, exhibit improved thermal stability and reduced sensitivity to temperature-induced performance losses. This improvement is likely due to better electric field formation and interface passivation, which mitigate recombination at the a-Si:H/c-Si junction. On the other hand, ultrathin FSF layers (< 5 nm) result in insufficient band bending and weak field effect passivation, thereby increasing interface recombination and significantly degrading the photovoltaic efficiency.Overall, the findings underscore the critical role of FSF layer thickness in determining the thermal and optoelectronic behavior of heterojunction solar cells. They highlight the need for simultaneous optimization of the FSF thickness and the cells thermal operating conditions to ensure stable and efficient performance under realistic environmental variations.