Structural and Optical Properties of Thin Films of Zn[sub x]Cd[sub (1−x)]S

Abstract

Films of the solid solution system ZnxCdfalse(1−xfalse)S have been produced by simultaneous evaporation from two separately controlled sources onto a single substrate. Films of uniform composition were made covering the full range from 0 to 100% normalZnS concentration, and the dependence of energy gap, crystal habit, and lattice parameter on composition was investigated. Optical transmission edge measurements yielded a nearly linear dependence of gap width on composition between the values of 2.35 ev for pure cadmium sulfide and 3.35 ev for pure zinc sulfide. X‐ray diffraction specimens were prepared by scraping the films from the substrates. The powder patterns obtained showed that a gradual transition from the wurtzite structure typical of CdS to the characteristic normalZnS zinc‐blende form takes place between 60 and 85% normalZnS concentration. At compositions where both modifications are present, the basal plane spacing is the same for the hexagonal (002) and cubic (111). Equivalent hexagonal lattice parameters could therefore be defined for the cubic form, and a and c calculated for all compositions. The results show good agreement with data obtained by others on bulk material.

ZnS , CdS , and Zn1 − x Cd x S Thin Films Deposited by the Successive Ionic Layer Adsorption and Reaction Process

“…There is a considerable disagreement in the literature concerning the variation of the lattice constants with composition (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29). The obtained phases and the variation of the lattice constants showed a marked and complicated dependence on the growth conditions.…”

Caractérisations structurale et optique de bicouches Cd1- yZnyS/CuPc : mise en évidence d'un effet photovoltaïque

“…] centrations : y = 0; 0,095 et 0,17. Les valeurs de Eg obtenues sont représentées sur la figure 10 où on a porté également les résultats des travaux effectués sur des couches similaires préparées par pulvérisation avec air [5,15,16] et par évaporation thermique [8]. Dans la région de composition considérées (0 y 0,2) les valeurs de Eg des couches fabriquées par les trois méthodes suivent la même loi de variation en fonction de la concentration en zinc, ces valeurs sont assez voisines pour une concentration déterminée (Tableau II), l'écart relativement important pour y = 0 est réduit pour les plus grandes concentrations.…”

“…8 Nos résultats : Pulvérisation chimique sans air (T, = 420 °C, 1 pm 5 e 4 um) ; x Réf. [8] : évaporation thermique (p = 3 x 10-6 torr, e = 0,5 pm) échantillon recuit à 450 °C pendant 15 min ; 0 Réf. [5] : pulvérisation chimique avec air (T. = 450 °C, e = 2um); A Ré£ [15] : pulvérisation chimique avec air (0,5 pm e 10 pm); 1 Réf.…”

“…e Our results : air less spray (Ts = 420 °C, 1 pm e 4 pm) ; x Réf. [8] : thermal evaporation (p = 3 x 10-6 torr, e = 0.5um) annealed sample at 450 °C during 15 min) ; 0 Réf. [5] : spray pyrolysis with air (Ts = 450 °C, e = 2nm); A Réf.…”

Synthesis of quantum-size cadmium-zinc sulfide particle-doped glasses by the sol-gel method

“…Tohge et al [2] performed the sulfuration of Cd and Zn introducing in the sol a methanolic solution of thiourea. Kane et al [3] have shown that a complete solid solution exists between ZnS and CdS in thin films. Barret et al [4] indicate that Zn forms a substitutional solid solution with CdS, shifting the band gap to higher energies.…”