Characterization of Low Temperature P-Type Hydrogenated Microcrystalline Silicon Thin Films Deposited by Plasma Enhanced Chemical Vapor Deposition

P-type hydrogenated microcrystalline silicon (muc-Si:H) thin films (~100 nm) were deposited using plasma enhanced chemical vapor deposition (PECVD) at a substrate temperature of 150degC. RF power density and pressure were varied among films. These films reach a dark conductivity (sigma_d) of 10^-1 S/cm, activation energy (E_a) of 10^-2 eV and crystalline volume fraction (X_c) of > 50 %. The structure of these films is composed of nano-sized crystallites embedded in an amorphous matrix, resulting in wide optical bandgap energies (E_opt). Using the Scherrer´s formula, grain sizes were estimated to be < 20 nm.