THE CHARGE STATE OF Cd DOPANT ON Ga2O3
Perturbed Angular Correlations allows probing the electronic distribution in the surroundings of a probe atom and determine its position and electronic configuration. 111In was introduced by diffusion at 1100 oC in Ga2O3 pellets. The PAC measurement occurs after electron capture decay of 111In into 111Cd, an envisaged dopant of Ga2O3, enabling the observation of the Cd electronic recovery after loss of an electron from the inner atomic K-L- shells. The measurements performed as a function of temperature show the recovery of the equilibrium, final electronic state, with an activation energy of 0.29(eV) and the existence of Cd atoms on an electronic intermediate state. The results were interpreted using Density Functional Theory, revealing the observed intermediate electronic state as a neutral Cd atom on octahedral Ga sites, and the final stable state being a Cd ion, with an extra electron, providing the first clear determination of an activated dopant in Ga2O3.