High open-circuit voltage (1.04 V) n-i-p type thin film silicon solar cell by two-phase silicon carbide intrinsic material

Abstract

We prepared two-phase hydrogenated silicon carbide (SiC:H) intrinsic materials from silane-methane gas mixtures at a low temperature of 150 °C using radio-frequency plasma enhanced chemical vapor deposition (RF-PECVD). We then employed Raman, HRTEM and FT-IR measurements to investigate the structural evolution of the resulting two-phase heterostructure films, and confirmed the medium range order of SiC:H materials based on the intensity of the transverse acoustic mode and microstructure factor. High concentration of medium order materials associated with nanocrystalline Si was obtained in the amorphous silicon carbide/nanocrystalline silicon hybrid layers. Under optimized deposition conditions, the intrinsic film has an optical band gap of up to ~2.0 eV and photosensitivity of up to ~4×106; these qualities make it an excellent intrinsic material to use when fabricating wide band gap top cells for multi-junction thin film silicon solar cells. Using both wide band gap window layers and intrinsic layers, a high open-circuit voltage of 1.04 V and short-circuit current density of 9.66 mA/cm2 were achieved for a single junction n-i-p solar cell on stainless steel. © 2014 Elsevier B.V. All rights reserved.