Zincblende type phase

At 225 K zincblende-type phase with a=5.82 coexists. See also Fig. 105. 

Thinner films a=6.48, zincblende-type. Thicker films additional wurtzite-type phase with a=4.57, c=7.47, c/a= 1.63 and a hexagonal phase with a=4.57, c= 11.27, c/a=2.47. 

Buckley used the same technique to deposit films for photovoltaic cells [113], only with CdCli as Cd source and apparently a lower Cd concentration. Electron diffraction of these films showed a predominantly zincblende structure with some wurtzite phase. The films were p-type with a resistivity of 20 5 fl-cm. These values, and the subsequent photovoltaic cells, apparently refer to as-deposited films no reference to annealing was made in this stndy. 

Bulk CdS possesses wurtzite structure ( 4 type) or zincblende structure ( 3 type). Both phases are formed by stacking of close-packed planes of cadmium and sulfur atoms. Hexagonal wurtzite structure can be represented as the periodic sequence AB AB AB... of closed-packed planes. Cubic zincblende is a sequence ABCABC... of closed-packed planes. For both structures the tetrahedral surrounding of both elements, cadmium and sulfur, takes place. According to the available literature data X-ray diffraction patterns of nanostructured CdS films and powders synthesized by different methods have similar features. Analysis of these features shows that the atomic structure of CdS nanoparticles differs from that of the bulk material. 

Under pressure (p 45kbar) transformation to NaCI-type and conversion to zincblende and wurtzite phase when pressure released (see Fig. 103). 

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