The p/i interface layer in amorphous silicon solar cells: a numerical modeling study

The Analysis of Microelectronic and Photonic Structures (AMPS) computer program was used to study the influence of the p/i interface layer an stabilized (p)a-SiC:H/(i) a-Si:H/(n) μc-Si heterojunction solar cell performance. The band gap, defect density, and doping variations in the p/i interface and their effects on the light J-V characteristic were examined. The greatest performance benefit could result from control of the recombination (mobility) gap of the interface region. Cells with interface layers with a recombination gap that is close to that of the p-doped layer have the best fill factors and Voc. We suggest that in designing high quality buffer layers the emphasis be placed on increasing the recombination band gap of the interface at the expense of concerns about interface defect density. Hydrogenated interface layers or microcrystalline SiC:H layers can provide increased band gap at the p-i heterojunction. Further, it may be possible to produce high quality cells in single chamber systems. Preliminary studies to determine the influence of interface layers on stability were initiated