Molecular beam epitaxy of p-type conducting ZnSe and ZnSSe by simple nitrogen gas doping without plasma activation

Abstract

Highly conducting p-type ZnSe and ZnSSe were fabricated by simple N2 gas doping during molecular beam epitaxial growth without the use of any activation method, such as discharge and cracking. p-type conduction in the N2-gas doped ZnSe is produced by a shallow N acceptor state, which is obtained only when the dopant N2 pressure is higher than 10−5 Torr. When the N2 pressure was varied from 3.2×10−5 to 1×10−4 Torr, the net acceptor concentration of N2-gas doped ZnSe and ZnS0.06Se0.94 films ranged from 3×1015 to 2×1017 cm−3 and from 1×1016 to 2.5×1017 cm−3, respectively. Light emitting diodes with a N2-gas doped p-cladding layer were fabricated and tested.