The diffusivity of the Cd interstitial in CdTe
The enhancement by Cu doping of the Cd self-diffusivity in CdTe (Ahmed et al 1996 J. Crystal Growth 160 36) is accounted for by enhanced concentrations of both Cd·i and Cd· ·i. The possible contribution of the Cd·i requires confirmation through more precise experimental data. It is also concluded that in the Cu doping experiments a fraction of the ionized Cu acceptor is in a neutral state. A review of high temperature Hall measurements of n, the free electron concentration, as a function of Cd pressure and of the relaxation of n following a step change in Cd pressure shows that any contribution of V· ·Te to the electro-neutrality condition in Cd-rich undoped CdTe as proposed by Fochuk et al (2006 J. Electron. Mater. 35 1354) is not supported by the evidence. The relaxation data provide values for the diffusivity of the Cd· ·i between 500 °C and 900 °C.