Band structure engineering of ZnO1-x Sex alloys

Abstract

ZnO1-x Sex alloys with Se substitutional composition x<0.12 were synthesized using pulsed laser deposition. Incorporation of small concentrations of Se results in a greater than 1 eV red shift in the ZnO optical absorption edge which is quantitatively explained in the framework of the band anticrossing model. The Se defect level is found to be located at 0.9 eV above the ZnO valence band and the band anticrossing coupling constant is determined to be 1.2 eV. These parameters allow prediction of the composition dependence of the band gap as well as the conduction and the valence band offsets in the full composition range of ZnO1-x Sex alloys. © 2010 American Institute of Physics.