Structural and optical properties of phosphorous doped nanocrystalline silicon deposited using a VHF PECVD process for silicon heterojunction solar cells and optimization of a simple p-n junction cell using SCAP-1D tool.

Abstract

Initially hydrogenated silicon (Si:H) thin films have been deposited using a plasma-enhanced chemical vapor deposition technique (PECVD) using silane (SiH4) as a precursor gas diluted in an inert gas argon (Ar) environment. Subsequently phosphine gas (PH3) was used as the n-type dopant and the deposition was carried out at a fixed substrate temperature of 200 °C. The PH3 flow rate was varied in the range of 0-1 sccm. The effect of PH3 flow rates on optical, electrical, and structural properties of hydrogenated amorphous and micro/nanocrystalline silicon films has been investigated and detailed analysis is presented. These films may find application in heterojunction solar cells as an emitter layer. Further, a crystalline silicon (c-Si) based simple p-n junction solar cell is simulated using an SCAP-1D tool to observe the effect of layer thickness and doping density on solar cell parameters.