Near infrared enhancement in CIGS-based solar cells utilizing a ZnO:H window layer.

We investigated the near infrared enhancement in Cu(In,Ga)Se2 (CIGS)- based solar cells utilizing a hydrogen-doping ZnO (ZnO:H) window layer. The results show that the carrier concentration of ZnO:H film is lower than that of AZO film which can increase the transmittance in the NIR. The advantage of ZnO:H film is higher Hall mobility than AZO film. Thus ZnO:H film has similar resistivity to AZO film. It was found that the cell efficiency was 12.4 and 13% for the AZO device and the ZnO:H device, respectively. The cell efficiency is enhanced by 4.8%. Furthermore, the results indicate that, the ZnO:H film is superior to the AZO film as the window layer for CIGS-based solar cells.