Growth of μc-Si active layer in a-Si/μc-Si solar cell: An optimization of growth process through modification of active layer near p/i interface

The growth of μc-Si active layer has been investigated in a-Si/μc-Si superstrate p-i-n solar cells. The growth of μc-Si i-layer seems to have considerable dependence on the immediate substrate it is growing on. In superstrate configuration, the p-layer of μc-Si cell in an a-Si/μc-Si cell should attain the required properties for doping, window, recombination layer, and for seed layer of μc-Si intrinsic layer growth in the bottom cell. An easy approach to fabricate μc-Si solar cells would be to decouple the requirements for a p-layer. In this article, a modification of the growth condition of μc-Si i-layer near the p/i interface has been demonstrated to fabricate a-Si/μc-Si solar cells starting with a non-optimized p-layer in terms of seeding requirements. The solar cell performance has been improved with this modification by decoupling the role of p-layer as seed layer for μc-Si growth. The structural properties of the i-layer have been investigated with Raman spectroscopy. An initial conversion efficiency of 11.3% has been achieved in this work.