✍ Scribed by R. Radojcic; A.E. Hill; M.J. Hampshire
No coin nor oath required. For personal study only.
A novel polycrystalline thin film solar cell based on alloys of CdS and CdTe is proposed and investigated. The structure consists of an n-type CdS~Tel _~ (0.5 < x < 1) surface layer with a graded composition and hence a band gap which varies between 2.4 eV and 1.5 eV. The base layer consists of homogeneous p-type CdTe or p-type CdS0.5Te0.5 of uniform band gap. An apparatus suitable for the vacuum deposition of the proposed structure is described which incorporates a novel technique to control the composition of the graded and mixed CdSxTe~ _x layers. The conductivity of both layers is controlled by simultaneous co-evaporation of suitable dopant materials. Preliminary results are presented, showing that in agreement with theoretical expectations the device exhibits a very wide spectral response. Copper electrodes used for contacting the p-type base layers were found, however, to be unsuitable because of the migration of copper atoms along the grain boundaries. Because of a lack of suitable contacting materials a solar cell with a sufficiently low series resistance has not as yet been produced.
📜 SIMILAR VOLUMES
An apparatus is described which is capable of depositing mixed semiconductor films by a novel co-evaporation technique. This was used to deposit a uniform mixed film of CdS~Tel x with various values of the composition factor x. Mixed films with the composition factor x varying from 0 to 1 were prepa
Cadmium sulphide and cadmium telluride films have been electrodeposited for n-CdS/p-CdTe solar cells. Cell efficiency varied considerably from 9.5% to 11.5% for each deposition set. The reverse saturation currents of 9.5% and 11.5% cells at 298 K were 25 and 6.7 nA cm -2, respectively. The cells wit