Light management for enhanced efficiency of textured n-i-p type amorphous silicon solar cell

Solar cell with textured front surface and back reflector, show enhanced current density due to improved light management. We investigated n-i-p type amorphous silicon solar cells that were deposited on pyramidally textured c-Si substrates. Additional Ag/AZO back reflector (BR) layers were also used in some cells, where AZO is aluminum doped zinc oxide. We estimated that an initial 27% enhancement in short circuit current density (Jsc) was due to improved light capture due to the surface texture (without the BR). With the smooth pyramidal BR the additional 0.82 mA/cm2 enhancement in Jsc is partly due to the reflection of unabsorbed light from the back to the cell, while for the cell deposited on multi textured BR a further improvement in the Jsc by 1.3 mA/cm2 was observed due to a further reduction in reflection loss of the incident light at the front surface of the cell. The quantum efficiency enhancement factor, which is considered an important parameter of light trapping, increases with the successive introduction of the BRs. We used a classical ray diagram to investigate the light inside the cell as well as AFORS HET computer simulation for estimating its electrical characteristics and wave optical numerical simulation was carried out to investigate behavior of light due to the various surface textures of the cells.