1. Aluminum-doped n-type ZnSTe alloy grown by molecular beam epitaxy
- Author
-
Sou, IK, Yang, Z., Mao, J., Ma, ZH, Tong, KW, Yu, P., Wong, GKL, Sou, IK, Yang, Z., Mao, J., Ma, ZH, Tong, KW, Yu, P., and Wong, GKL
- Abstract
Successful n-type doping of ZnSTe alloy using elemental aluminum source has been carried out by molecular beam epitaxy. Hall effect measurement (300-77 K) was performed on as-grown ZnS0.977Te0.023 epilayers with various dopant concentrations. Electron carrier concentration as high as 1.3X10(19) cm(-3) has been achieved. For carrier concentration higher than 5X10(18) cm(-3), the carrier concentration is independent of temperature, possibly indicating formation of a very shallow donor level. A group of ZnS1-xTex epilayers with different x values was doped using a constant aluminum beam flux for studying the dependence of the dopant activation on Te composition. Good activation of Al dopant was obtained for x value from 0 to a few percent, but it became poor for larger x value and finally Al became inactive for x values higher than 10\%. Room temperature photoluminescence measurements on doped and undoped ZnS and ZnS1-xTex layers indicate that Al dopants from deep-level radiative centers in addition to a shallow donor level. The characteristics of these deep levels as a function of Te composition have also been studied. (C) 1996 American Institute of Physics.
- Published
- 1996