Some optical and electrical measurements on blue fluorescent ZnS-Cl single crystals

Abstract

For hexagonal ZnS-Cl single crystals, measurements of the intensity of luminescence, photo-conductivity, Hall effect, thermo-luminescence and thermo-conductivity have been carried out. Analysis of the experimental results provides the following data: a) the electron mobility at room temperature μ c ≈= 120 cm 2 V −1 sec −1 ; the mobility decreases with increasing temperature, b) the depth of traps formed by Cl − is ɛ Cl − = 0.24 ± 0.02 eV, c) the frequency of escape from Cl − traps s = 7. 10 4 sec −1 d) the capture cross-section of the Cl − traps is σ ≈= 3.10 −21 cm 2 e) recombination levels (“killers”) are situated ∼ 0.7 eV below the conduction band.