Influence of Background Impurities of Oxygen and Copper on The Luminescence Spectrum of Polycrystalline CVD ZNSE with Excess Selenium

The influence of background impurities of oxygen and copper on the luminescence spectrum of polycrystalline chemical vapor deposition (CVD) ZnSe with excess selenium excited from different points of the sample surface by different sources at room temperature has been studied. Furthermore, the degradation process with time on the surface of a CVD ZnSe sample with excess selenium has been examined and it has been demonstrated that this process occurs more rapidly on the unpolished sample surface. By changing the wavelengths of the exciting light with a certain step, it is possible to excite all the multizones in the crystals under study, as a result of which luminescence spectra corresponding to a shift along the energy scale of the band model with a corresponding change in the type of emission transitions are observed. The DFT calculations have been used to investigate the changes in the band gap first when replacing two selenium atoms with oxygen atoms, then simultaneously when replacing two selenium atoms with oxygen atoms and two zinc atoms with copper atoms. The luminescence intensity decay at maxima of the green region of the spectrum was measured using the time-correlated single photon counting (TCSPC) method.