Published online by Cambridge University Press: 15 February 2011
The optimum deposition conditions for growth of amorphous silicon (a-Si:H) and silicon-germanium (a-SiGe:H) alloys deposited at high rates using microwave glow-discharge are found to be quite different from those for radio-frequency glow-discharge material deposited at low rates. High substrate temperature (350 to 500 °C), low pressure (1–5 mtorr) and positive ion bombardment are found to be desirable for optimum growth conditions at high deposition rates. We have achieved an active-area efficiency of 11.44% for a double-junction structure in which the bottom cell incorporates a-SiGe:H alloy deposited at 100 Å/sec using microwave glow-discharge.