Improvement of Rear Surface Passivation Quality in p-Type Silicon Heterojunction Solar Cells Using Boron-Doped Microcrystalline Silicon Oxide

摘要

Boron-doped microcrystalline silicon oxide (μc-SiO_x:H) films for application as a back surface field (BSF) in p-type silicon heterojunction (SHJ) solar cells have been characterized. We found that the (iC-SiOx:H(p) film at the optimized condition shows high conductivity and good passivation effect with a low surface recombination velocity of around 10~2cm/s. However, too much oxygen atoms in the films increase the defect and the passivation quality degrades. Thus, the control of oxygen content in the films is very important to obtain a high passivation quality. With applying the μc-SiO_x:H(p) as a BSF layer leads to improved p-type SHJ solar cells performance, which shows the enchantment of EQE spectra in long wavelengths between 800 and 1200nm. The highest efficiency of the p-type SHJ solar cell we obtain is 18.5% (active area = 0.88 cm2) with a V_oc = 659mV, J_sc = 34.7mA/cm~2, and FF = 80.9%.