Hot-wire chemical vapor deposition and characterization of p-type nanocrystalline SiC films and their use in Si heterojunction solar cells

Wide optical bandgap p-type nanocrystalline silicon carbide (p-nc-SiC) films deposited by hot-wire chemical vapor deposition were used as window layers in n-type crystalline Si heterojunction (HJ) solar cells. The effect of H2 flow rates on the material properties of p-nc-SiC films was investigated by X-ray diffractometer and Raman spectroscopy. Moreover, the optical and electrical properties, such as optical bandgap (Eg), dark conductivity, and activation energy (Ea), of p-nc-SiC films were also measured. It was found that H2 flow rates played an important role in forming of p-nc-SiC films and increasing the Eg and decreasing the Ea of p-nc-SiC films. Moreover, the effect of hydrogenation process of the amorphous Si buffer layer on solar cell characteristics was investigated. After the deposition and hydrogenation parameters were optimized, the Si HJ solar cells with the open-circuit voltage of 0.59 V, short-circuit current density of 38.06 mA/cm2, fill factor of 62.03%, and the conversion efficiency of 14.09% could be obtained.