Fabrication of P-Type Microcrystalline Silicon Thin Film by Magnetron Sputtering and Copper Induced Crystallization

Abstract

$P$ -type micro-crystalline Silicon thin film was realized by magnetron sputtering and copper-induced crystallization for photovoltaic applications. Firstly, amorphous Silicon film was deposited by direct current magnetron sputtering from highly-doped single crystalline Si target. Then it was crystallized by copper-induced crystallization in nitrogen atmosphere with the annealing temperatures ranges from 450 to 950°C. The microcrystalline Silicon thin film was characterized by X-ray diffraction and Ramon spectrometry. Its grain size and crystallization ratio were approximately 20 nm and 93%, respectively. Finally, a PN junction solar cell was fabricated by creating the P-type microcrystalline Si thin film (as the $P$ region) on a highly-doped N-type Silicon wafer (as N region). The fabricated device showed the good rectification characteristics of a typical diode where under dark condition it represented the rectification ratio of 150 and reverse saturation current density of 9 μA.cm-2. The fabricated solar cell showed a significant photovoltaic effect under AM 1.5G illumination conditions. The highest photovoltaic conversion efficiency of 2.1%, with the open-circuit voltage of 416 mV and short-circuit current density of 13.3 mA/cm2, was measured from the sample fabricated by the optimal process.