p-Type doping of II-VI heterostructures from surface states: application to ferromagnetic Cd${}_{1-x}$Mn${}_x$Te quantum wells

Abstract

We present a study of p-type doping of CdTe and Cd${}_{1-x}$Mn${}_x$Te 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${}_x$Te 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.

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