Composites consisting of hydrogenated amorphous silicon (a-Si: H, inorganic) and zinc phthalocyanine (ZnPc, organic) were prepared by vacuum evaporation of ZnPc and sequential deposition amorphous silicon via plasma enhanced chemical vapor deposition (PECVD). The optical and electrical properties of the composite film have been investigated. The results demonstrate that ZnPc can endure the temperature and bombardment of the PECVD plasma and photoconductivity of the composite film was improved by 89.9% compared to pure a-Si: H film. Electron mobility-lifetime products μτ of the composite film were increased by nearly one order of magnitude from 6.96 × 10-7 to 5.08 × 10-6 cm2/V. Combined with photoconductivity spectra of the composites and pure a-Si: H, we tentatively elucidate the improvement in photoconductivity of the composite film.
Boron-doped hydrogenated silicon films with different gaseous doping ratios(B2H6/SiH4) were de-posited in a plasma-enhanced chemical vapor deposition(PECVD) system.The microstructure of the films was investigated by atomic force microscopy(AFM) and Raman scattering spectroscopy.The electrical properties of the films were characterized by their room temperature electrical conductivity(σ) and the activation energy(Ea).The results show that with an increasing gaseous doping ratio,the silicon films transfer from a microcrystalline to an amorphous phase,and corresponding changes in the electrical properties were observed.The thin boron-doped sili-con layers were fabricated as recombination layers in tunnel junctions.The measurements of the I-V characteristics and the transparency spectra of the junctions indicate that the best gaseous doping ratio of the recombination layer is 0.04,and the film deposited under that condition is amorphous silicon with a small amount of crystallites embedded in it.The junction with such a recombination layer has a small resistance,a nearly ohmic contact,and a negligible optical absorption.
