Growth And Characterizations Of Solid Solutions Semiconductor Of Polycrystalline ZnMgS Thin Films

ZnS is a kind of important II-VI direct band-gap semiconductor materials(3.6eV at room temperature).it has comparatively large exciton binding energy of 40meV. ZnS is a kind of very promising materials for making the optoelectronics devices such as UV/blue light-emitting diodes and short-wavelength semiconductor diode laser devices being developed and put in application. The solid-solution ZnMgS can be formed by introducing Mg into ZnS and filling in it. It can have different luminescence wavelength, crystal lattice parameter and band gap. These characteristic are key to designing and making semiconductor optoelectronics devices. So it is all-important to research solid-solution semiconductor ZnMgS materials.Solid solution polycrystalline Zn_1-xMg_xS thin films were grown successfully on amorphous quartz glass and ITO glass substrates by vacuum evaporation and it has different content of Mg. The compositions, structures, morphologies and optical characterizations of the thin films were investigated by EDS, XRD, Raman, AFM, UV-visible absorption spectra and PL spectra and the results indicate that Zn_1-xMg_xS thin films have uniformly morphology and show a (111) oriented zinc-blend structure. The films have very strong absorption in the short wavelength range and the absorption edge is about between 356 and 275nm.And deducting the expression of band-gap: E_g(x) =0.6869x²+0.2131x+3.6. PL peaks locate between 420 nm and 395nm without other emission at room temperature. With increasing of Mg component, (111) peaks move a little to large angle, the absorption edge and PL peak are found blue shift obviously, which indicate band-gap becomes wide and it increases from 3.60ev to 4.1ev. According to these characterizations, it is concluded that Zn_1-xMg_xS thin films are promising materials for short wavelength optoelectronic applications and ultraviolet detectors. The structures, morphologies, optical and electrical characterizations of the films prepared on ITO glass by investigating are all right. It shows important sense and considerable application foreground to carrying out field emission-flat display and photoluminescence and electroluminescence devices at the same time.