Hydrogenated Microcrystalline Silicon Single-Junction Nip Solar Cells

Abstract

The microstructural properties of hydrogenated microcrystalline silicon solar cells are investigated using Raman spectroscopy and x-ray diffraction. It was found that the increase of grain size and crystalline volume fraction with thickness is the main reason for the deterioration of cell performance as using constant hydrogen dilution technique. In order to adjust grain size and crystalline volume fraction along the growth direction, gradient hydrogen dilution technique has been adopted to control the structural evolution. The experiment results demonstrated that the performance of solar cell can be much improved when there’s a higher crystallinity at n/i interface and a lower crystallinity at i/p interface. We have achieved an initial active-area efficiency of 5.7% (Voc=0.47V, Jsc=20.2mA/cm2, FF=60%) for the µc-Si:H single-junction n-i-p solar cells.