P- and n-type conductivity domains in dual-doped ZnO:As+N layers grown by metal organic vapor phase epitaxy on GaN–sapphire templates were electrically microcharacterized by scanning capacitance microscopy (SCM) and scanning surface potential microscopy (SSPM) techniques with respect to their defect states. The p-type domains were found to be dominated by two acceptors with thermal activation energies of about 80 and 270 meV, as observed by transient SCM scans at different temperatures. Optically excited SSPM scans revealed defect-to-band transitions at 400, 459, and 505 nm omnipresent in both domain types as well as a shallower transition at 377 nm exclusively in the p-type regions. According to the similar energy levels, the optical transitions at 377 and 400 nm are assigned to acceptor states, whereby the 80-meV acceptor is probably responsible for the conversion from n- to p-type regions in the domains.

P- and n-type conductivity domains in dual-doped ZnO:As+N layers grown by metal organic vapor phase epitaxy on GaN/sapphire templates were electrically microcharacterized by scanning capacitance (SCM) and scanning surface potential microscopy (SSPM) techniques with respect to their defect states. The p-type domains were found to be dominated by two acceptors with thermal activation energies of about 80 and 270 meV as observed by transient SCM scans at different temperatures. Optically excited SSPM scans revealed defect-to-band-transitions at 400, 459, and 505 nm omnipresent in both domain types as well as a shallower transition at 377 nm exclusively in the p-type regions. According to the similar energy levels the optical transitions at 377 and 400 nm are assigned to acceptor states, whereby the 80meV-acceptor is probably responsible for the conversion from n- to p-type in the domains.

Deposition of amorphous germanium by anodic PCVD was performed changing the germane/hydrogen dilution ratio from 1/6 to 1/100. Films deposited under high dilution of germane are of a high mechanical density (92.5 % of bulk) and good optoelectronic properties (electrical conductivity at room temperature σ=10−5 (Ω cm)−1, majority carrier mobility-lifetime product at λ=1200 nm ημ=x 10−7 cm2/V). The quality of the films is increased by deposition at increasing pumping speed for hydrogen (lower hydrogen pressure) keeping the other parameters constant. It is suggested that fast atomic hydrogen originating from a backscattering process at the powered electrode bombard the growing film and contribute to the improved quality of the a-Ge:H. Also, the growth kinetics of the films is changed from linear to parabolic dependence on germane flow interchanging deposition from high to low hydrogen pressure. This effect is rationalized in terms of a contribution of energetic atomic hydrogen to the dissociation of germane.