MBE growth of ZnSSeO alloy using ZnS as a sulfur source

We have grown quaternary alloy semiconductor ZnSSeO by molecular beam epitaxy. Large band gap bowing due to large electronegativity of O is expected in this alloy. The growth of ZnSSeO was proceeded by supplying RF-excited oxygen during the growth of ZnSSe. The lattice constant of ZnSSeO decreased with increasing O 2 flow rate. X-ray diffraction peak was separated when O 2 flow rate was high. However, controllable range of lattice constant without phase separation was expanded compared with ZnSeO ternary alloy. It was shown that S composition parasitically increased with O composition. We have explained the enhancement of S incorporation in terms of reduction of strain energy. The band gap energy decreased with increasing O 2 flow rate regardless of phase separation. The amount of band gap bowing was slightly less than that found in ZnSeO.