We present the photoluminescence spectra obtained in the case of normal incidence of exciting radiation at both polished and unpolished surfaces of chemicalvapour deposited ZnSe films in the temperature range 12-300 K. The luminescence has been excited using either a continuous-wave He-Cd laser with the wavelength λ ex = 325 nm (i.e., under the condition hv ex > E g for the photon energy) or a semiconductor laser with λ ex = 532 nm (i.e., hv ex < E g). We show that the temperature dependences of intensity, spectral position and half-width of a green photoluminescence band detected in the both alternative cases are very different in the region 12-80 K. However, their behaviours become very close to each other when the temperature increases up to 180 K. Finally, the above spectral parameters are almost the same in the region 180-300 K.
Photoluminescence (PL) spectra measurements have been carried out in the ternary chalcopyrite semiconductor compounds ZnGa 2 Se 4 and ZnGa 2 Se 4 :Eu 2+ using single-wavelength excitation of a Hg lamp with = 365 and 375 nm.Measurements were performed at the temperature range of (120 -220 K) and (110 - ), energy of optical phonons (h = 25 -30 meV), Huan Rice parameter (S = 8 -10), energy of thermal quenching (E = 0.02 -0.06 eV) were determined from the temperature dependences of the full width at half maximum (FWHM = Г(T)).
Spectroscopic ellipsometry has been applied at room temperature to a multilayer device structure with plain and nanograting‐embedded Si layer on the top. In both cases, the real and imaginary parts of the complex dielectric function of the top layer have been retrieved. In nanograting case, ellipsometric data were collected in planar diffraction geometry. A profound change in dielectric function in the photon energy region between 1.5 and 3.5 eV is established for nanograting‐embedded Si layer compared to plain Si layer. Both real and imaginary parts of the former are no longer Si‐like and resemble more those for metals. The maximum of interband density‐of‐states for optical transitions is positioned at 2.1 eV and coincides with the energy of optical transitions from the main irradiative eigenstate. The obtained results are discussed in terms of geometry‐induced doping changes in interband density of states.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.