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.
This paper studies the electronic structure and native defects in transparent conducting oxides CuScO 2 and CuYO 2 using the first-principle calculations. Some typical native copper-related and oxygen-related defects, such as vacancy, interstitials, and antisites in their relevant charge state are considered. The results of calculation show that, CuMO 2 (M = Sc, Y) is impossible to show n-type conductivity ability. It finds that copper vacancy and oxygen interstitial have relatively low formation energy and they are the relevant defects in CuScO 2 and CuYO 2 . Copper vacancy is the most efficient acceptor, and under O-rich condition oxygen antisite also becomes important acceptor and plays an important role in p-type conductivity.
