High p-type doping level of MgZnCdSe on InP substrates by inserting ZnTe thin layers

A novel p-type doping method for MgZnCdSe on InP substrates was proposed. In this method, highly p-type-doped thin layers, such as N-doped ZnTe, are inserted at proper intervals into MgZnCdSe layers. The inserted thin layer emits holes and the p-type coduction was achieved. ZnCdSe/ZnTe superlattices (SLs), where thin p-type-doped ZnTe layers were periodically inserted, were grown on InP substrates by molecuar beam epitaxy. When the ratio of ZnTe layer thickness to one insertion period was 0.17, the net acceptor cocentration (N_A-N_D) value reached 8.0 × 10¹⁷ cm^–3. This value was more than one order of magnitude greater than that of a simple N-doped ZnCdSe layer (3.5 × 10¹⁶ cm^–3). To obtain wide bandgap p-type materials, MgSe/ZnCdSe/ZnTe SLs were fabricated. N_A-N_D values from 4.7 × 10¹⁷ to 8.0 × 10¹⁷ cm^–3 were observed for samples with bandgap energies from 2.33 to 2.04 eV. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)