Plasma nitrogen doping of ZnTe, Cd1−xZnxTe, and CdTe by molecular beam epitaxy

The p-type doping of ZnTe, CdTe, and Cd1−xZnxTe (CZT) using a nitrogen dc plasma source during growth by molecular beam epitaxy is demonstrated. For ZnTe, doping levels as high as 1020 cm−3 were achieved. In CZT alloys, a progressive decrease of the maximum doping level is observed for decreasing Zn content. Using pulse doping methods, a doping level of p≊3×1018 cm−3 is obtained for a 12% Zn CZT layer. For CdTe layers, the highest level achieved is p≊1017 cm−3. The progressive acceptor compensation phenomenon is discussed with emphasis on the role of the lattice distortion on the nitrogen incorporation mechanisms.