(015004)Al_2O_3/MoO_x Hole-Selective Passivating Contact for Silicon Heterojunction Solar Cell

摘要

Carrier selective contact (CSC) layers have been extensively studied to realize high passivation effect in solar cells. Excellent passivation properties of Al_2O_3 and a-Si:H(i) as passivating interlayers between the hole-selective contact (HSC) MoO_x and p-type c-Si wafer surface are reported herein. MoO_x single layer exhibits a high work function value (>=5.0 eV), which can cause sufficient band bending in the band structure for HSC. An Al_2O_3/MoO_x contact exhibits a significantly higher transmittance and surface passivation compared with that of an a-Si:H(i)/MoO_x contact. The passivation results for Al_2O_3/MoO_x contact are a carrier lifetime (τ_(eff)) of 830 μs and implied open circuit voltage (iV_(OC)) of 726 mV, whereas for conventional a-Si:H(i)/MoO_x contact, the corresponding values are 770 μs and 716 mV. Delicate thickness optimization was performed using experimental and simulation results for Al_2O_3/MoO_x and a-Si:H(i)/MoO_x stacks to achieve high performance in p-type c-Si solar cells.