A simulation study of p-i-n amorphous silicon photovoltaic cell using ZnO nano rods

Thinning down the active absorber layer is the current trend in solar cell technology. The thinner absorber layer has two main advantages (i) it reduces the material consumption and (ii) minimizes the time and energy required in production. For thin film silicon (Si) technology, thinning down the absorber layer is of particular interest since the device throughputs of vacuum deposition systems as well as the stability of the devices are significantly enhanced. The 3D nanorod structure in thin-film photovoltaics has got much attention due to their enhanced light trapping capability, and it also requires less thick active layer. The enhanced light trapping results in more efficient absorption of spectrum within the solar cell structure. This gives the higher short circuit current and hence higher power conversion efficiency. We have developed the ZnO nanorods on the glass substrate through galvanic cell based approach and designed a nanorod solar cell through numerical simulations using technology computer aided design (TCAD) tool. Numerical simulation shows that the highest conversion efficiency of 9.12% is obtained for the zinc oxide nanorod solar cell which is nearly 18.59% more than the planar a-Si:H solar cell with same absorber layer thickness.