Compositional control, band gap evaluation and acceptor doping characterization for ZnSeTe have been studied. Zinc selenotelluride layers were grown on GaAs (100) substrates by atmospheric metalorganic chemical vapor deposition. The composition of the ZnSexTe(1-x) solid is proportional to the gas phase composition when the VI/II ratio is close to unity. Accurate band gap energy values for ZnSeTe epilayers were obtained at room temperature by photoreflectance spectroscopy. The bowing parameter is 1.647 eV. The p-type carrier concentration of ZnSeTe : As is drastically quenched with increasing Se incorporation. The quenching is possibly attributable to the lattice distortion.