Papers by Keyword: Metal-Semiconductor Contact

Abstract: VI semiconductors are promising nanomaterials for applications as window layers in low-cost and high-efficiency thin film solar cells. These nanoparticles are considered to be the model systems for investigating the unique optical and electronic properties of quantum-confined semiconductors. The electrical and optical properties of polymers are improved by doping with semiconductor materials and metal ions. In particular, nanoparticle-doped polymers are considered to be a new class of organic materials due to their considerable modification of physical properties. In this paper, I review the present status of these types of Inorganic/Organic hybrid nanocomposite materials. CdSe nanorods dispersed in polyvinyl alcohol (PVA) matrix have been prepared by chemical routes. Different characterization techniques like structural, optical and electrical have been used to characterize these nanocomposites. The devices like Schottky diodes and MOS structures have been fabricated and the results have been discussed in this review. The results have been compared with the reported literature by other groups also. Table of Contents

Abstract: The structural characteristics of Au-TiB ₂/GaAs and Au-Mo-TiB₂-AuGe/GaAs device structures after deposition and short-term thermal annealing (STTA) were investigated. The multilayer contacts with TiB₂ anti-diffusion layer were magnetron sputtered on (001) GaAs substrates. The structures were STTA in a stream of hydrogen at temperatures of 400°C, 600°C, and 800°C during 60 seconds. The X-ray diffraction techniques and atomic force microscopy were used for investigation. At STTA a reduction of residual strain in multilayer metallic films, an increment of film grain size, a change of grains preferred orientation in the Au polycrystalline film and a transformation of surface morphology of the upper Au film were observed. These processes do not have monotonic temperature dependence. For Au-TiB₂/GaAs a minimum value of residual strains was observed at T=600°C while for Au-Mo-TiB₂-AuGe/GaAs it was observed at T=400°C. The roughness of Au film monotonically increased at annealing of Au-TiB₂/GaAs structure at T=400°C and T=600°C and corresponded to the initial value at T=800°C. A strong change of Au film roughness was observed at annealing of Au-Mo-TiB₂-AuGe/GaAs structure at T=600°C. The XRD pattern from a Au-TiB₂ metal film denoted a quasi-amorphous structure in the initial state and an increment of micrograins size at STTA. In the initial state the crystalline structure of Au film in Au-Mo-TiB₂-AuGe/GaAs structure had some preferred orientation in the <111> direction, which was reduced after STTA at T=600°C. The polycrystalline structure of Au film was partially deteriorated after STTA at T=800°C as TiB₂ layer was destroyed and lost its diffusion protecting properties.