Hydrogen-plasma reactive flush for a-Si:H and a-SiGe:H solar cell fabrication

An investigation is made of the effects of using a hydrogen plasma to reactively flush the reactor chamber between the p and i-layer depositions in fabricating solar cells of glass/SnO₂:F/p(a-SiC:H)-i-n(a-Si:H)/metal in a single-chamber, glow-discharge deposition system. The i layer is either intrinsic a-Si:H or a-SiGe:H. Solar cells made with the hydrogen-plasma flush process show improvements in short-wavelength responses and overall conversion efficiency. Photoluminescence measurements show reduction of defects at the interface of p and i layers by the hydrogen-plasma flush. The hydrogen-plasma process shifts the emission peak to higher energies by 25 meV, which indicates reduced disorder in a-Si:H