Abstract
Single crystals of oxygen-incorporated ZnS (i.e., ZnS((1-x))O (x) series) are environment-friendly wide-band-gap semiconductors available for light-emitting devices and solar cell use. The series of materials has considerable potential for use in visible ultraviolet areas with flexibility for palette emissions. In this study, we grow oxygen-incorporated ZnS series crystals by chemical vapor transport method with iodine (I(2)) as the transport agent. Three different oxygen-incorporated crystals of undoped ZnS, ZnS(0.94)O(0.06), and ZnS(0.88)O(0.12) are studied. Through structural studies, ZnS doped with oxygen crystallizes in the main sphalerite phase and a little wurtzite structure. The lattice constants of the major cubic phase are determined to be a = 5.43 Å (ZnS), 5.41 Å (ZnS(0.94)O(0.06)), and 5.39 Å (ZnS(0.88)O(0.12)). Three band-edge excitonic transitions are simultaneously detected by thermoreflectance measurement for the ZnS, ZnS(0.94)O(0.06), and ZnS(0.88)O(0.12) series samples. The energy positions of the band-edge transitions decrease as the oxygen content increases in the ZnS((1-x))O (x) series. Defect-state and surface-state emissions, including sulfur vacancy, oxygen vacancy, zinc interstitial, and so forth, can emit approximately full-color spectra from the near band edge of the ZnS((1-x))O (x) series crystals. With adjusting the oxygen content, the ZnS((1-x))O (x) can be a series of color-palette luminescence matters that applied for fluorescent display or light-emitting device.