Influences of oxygen contamination on evaporated poly-Si thin-film solar cells by solid-phase epitaxy

Abstract

The influences of the oxygen contaminations on the crystal quality and performances of the evaporated polycrystalline silicon (poly-Si) thin-film solar cells prepared by solid-phase epitaxy were investigated by applying different deposition rates and base pressures. The experimental results show that although the evaporated poly-Si thin-film solar cell obtained at high base pressures (9.33 × 10 − 5 Pa) and high deposition rate (300 nm/min) has small amount of SiO 2 precipitations, it still shows the similar good material quality and performances as the cell prepared at low base pressure (1.33 × 10 − 6 Pa) and high deposition rate (300 nm/min) with oxygen interstitials. On the other hand, the poly-Si thin-film solar cell deposited at low base pressure (1.33 × 10 − 6 Pa) and low deposition rate (50 nm/min) has large amount of SiO 2 precipitations and resulting worse material quality and hence cell performances. Therefore, the high deposition rate is desirable to maximize the solar cell performance, as well as the throughput. It is a more influential factor than the base pressure.