Microcrystalline Silicon Prepared by VHF-GD: Structure, Transport and Optical Properties

Abstract

ABSTRACTDoped and compensated microcrystalline silicon prepared by Very High Frequency Glow Discharge has been investigated by optical spectroscopy and by temperature dependence of the electrical conductivity. Raman spectroscopy confirms the microcrystalline nature of all samples with only small changes of the crystalline volume fraction upon doping. Strong absorption in the infrared region, which correlates with the conductivity, is attributed to free carrier absorption. As a function of temperature the conductivity of all samples shows a deviation from a purely activated behaviour. Consequences of this observation for transport mechanisms are discussed.