Increasing the photo-generated current in solar cells with passivating contacts by reducing the poly-Si deposition temperature

This paper investigates the reduction of the parasitic absorption in solar cells with poly-silicon based passivating contacts. We analyze the transparency of poly-Si films fabricated at various deposition temperatures. We observe different surface morphologies by scanning electron microscopy and model their spectroscopic ellipsometry reflection data. Based on the measured optical parameters (n and k) we perform ray tracing simulations for quantifying the expected increase of short-circuit current density of a cell. Our study shows that the poly-Si deposition at 530 °C leads to an increase of the photo-generated current density by up to 0.76 mA/cm² when compared to poly-Si films deposited at 610 °C.This paper investigates the reduction of the parasitic absorption in solar cells with poly-silicon based passivating contacts. We analyze the transparency of poly-Si films fabricated at various deposition temperatures. We observe different surface morphologies by scanning electron microscopy and model their spectroscopic ellipsometry reflection data. Based on the measured optical parameters (n and k) we perform ray tracing simulations for quantifying the expected increase of short-circuit current density of a cell. Our study shows that the poly-Si deposition at 530 °C leads to an increase of the photo-generated current density by up to 0.76 mA/cm² when compared to poly-Si films deposited at 610 °C.