Performance of All-Back-Contact Nanowire Solar Cell with a Nano-Crystalline Silicon Layer

In this communication, few approaches based on structural modifications of silicon solar cell (SC) are made to improve its performance. With respect to a conventional planar p-n junction type SC, a cylindrical nano wire solar cell (NWSC) is much more efficient in separating and collecting photo-generated carriers. Shifting of front contacts to the rear surface of such structures eliminates optical shadowing effects and can further improve the performance of such NWSCs. By adding a nano-crystalline silicon layer between p and n-layers of the p-n junction, light trapping and hence, the carrier generation rate are enhanced leading to improved efficiency. Thus, an all-back-contact NWSC with embedded nano-crystalline silicon layer performs best and shows up to 30% improvement in efficiency over that in a conventional NWSC. For comparison, all the above structures are simulated using CST Microwave studio, MATLAB, and TCAD tools with tight meshing strategy for generating the optical profile and electrical test run.