Effective nitrogen doping of a—Ge: H films prepared by DC-magnetron sputtering

Abstract Nitrogen incorporation below 2 at% into magnetron sputtered a—Ge: H increases the dark conductivity from 3·10 -6 (Ωcm) -1 to 3·10 -1 (Ωcm) -1 at maximum. The density of defect states detected by PDS increases proportional to the square root of nitrogen partial pressure. It is suggested that nitrogen-hydrogen complexes acting as donor states are responsible for this doping effect. Comparative investigations on nitrogen and phosphorus doped a—Ge: H show a higher doping efficiency, larger maximum dark conductivity and stronger structural disorder for nitrogen doping performed under identical preparation conditions.