p-Type doping of II-VI heterostructures from surface states: application to ferromagnetic Cd_{1-x}Mn_xTe quantum wells
W. Maslana, M. Bertolini, H. Boukari, P. Kossacki, D. Ferrand, J.A. Gaj, S. Tatarenko, J. Cibert
Abstract
We present a study of p-type doping of CdTe and Cd_{1-x}Mn_xTe quantum wells from surface states. We show that this method is as efficient as usual modulation doping with nitrogen acceptors, and leads to hole densities exceeding 2 \times 10^{11} cm^{-2}. Surface doping was successfully applied to obtain carrier-induced ferromagnetism in a Cd_{1-x}Mn_xTe quantum well. The observed temperature dependence of photoluminescence spectra, and the critical temperature, correspond well to those previously reported for ferromagnetic quantum wells doped with nitrogen.