Heavily p-type doped ZnSe and ZnBeSe

Modulation growth techniques (delta-doping) with the use of Te and N co-doping have been investigated to enhance the p-type doping of ZnSe and ZnBeSe. The highest net acceptor concentration achieved was 6 x 10(18) cm(-3) in ZnSe and 1.5 x 10(18) cm(-3) for ZnBeSe when a triple delta-doping technique was used. The resultant layers have an average Te content of less than 3% and as low as 0.5% in some of the epilayers. We present results of C-V, I-V, and photoconductivity measurements that suggest high free carrier concentrations and low acceptor activation energy. We also discuss low temperature photoluminescence (PL) studies, which show that while the dominant PL is due to N impurities and of donor-acceptor pair type, some emission peaks related to Te-2 clusters and/or Te-ngreater than or equal to3 clusters are also present.