Efficiency Enhancement of Multicrystalline Silicon Solar Cells by Inserting Two-Step Growth Thermal Oxide to the Surface Passivation Layer

Abstract EN

In this study, the efficiency of the multicrystalline was improved by inserting a two-step growth thermal oxide layer as the surface passivation layer.

Two-step thermal oxidation process can reduce carrier recombination at the surface and improve cell efficiency.

The first oxidation step had a growth temperature of 780°C, a growth time of 5 min, and with N2/O2 gas flow ratio 12 : 1.

The second oxidation had a growth temperature of 750°C, growth time of 20 min, and under pure N2 gas environment.

Carrier lifetime was increased to 15.45 μs, and reflectance was reduced 0.52% using the two-step growth method as compared to the conventional one-step growth oxide passivation method.

Consequently, internal quantum efficiency of the solar cell increased 4.1%, and conversion efficiency increased 0.37%.

These results demonstrate that the two-step thermal oxidation process is an efficient way to increase the efficiency of the multicrystalline silicon solar cells.