Band gap properties of Zn1−xCdxO alloys grown by molecular-beam epitaxy

Optical absorption and reflectance measurements are performed to evaluate compositional and temperature dependences of band gap energies of Zn1−xCdxO alloys grown by molecular-beam epitaxy. The compositional dependence of the band gap energy, determined by taking into account excitonic contributions, is shown to follow the trend Eg(x)=3.37−2.82x+0.95x2. Incorporation of Cd was also shown to somewhat slow down thermal variation of the band gap energies, beneficial for future device applications.