Development of a method for producing effective solar elements CdS/CdTe/Cu/Au on a flexible substrate designed for backup supplying systems prevention of emergency situations

Abstract

The technology of forming film solar cells based on CdS/CdTe configuration of the "superstrat" type on a flexible substrate has been improved. To increase the efficiency of the developed solar cells on a flexible substrate, a chemical etching procedure in a nitrogen-phosphorus mixture was added to the traditional "chemical treatment". The conducted studies of the output parameters of the developed device structures showed that the highest values are observed in the case of chemical etching, both before the "chloride treatment" and after it. In the course of the study, it was found that a mandatory procedure in the formation of effective device structures is chemical etching in a nitrogen-phosphorus mixture both before the "chloride treatment" and after it. Carrying out the described procedures made it possible to obtain solar cells on a flexible substrate with an efficiency of 13.1 %. The increase in the efficiency of solar cells with two-stage chemical etching can be explained by the formation of excess tellurium on the surface, which leads to a decrease in resistance and, therefore, to a more efficient penetration of chlorine during the subsequent chloride treatment. Analysis of the transverse cleavage of the investigated device structures demonstrates significant grain growth and surface smoothness of the base layer, which ensures good adhesion with back contact. A study of the degradation resistance of the developed device structures during operation has been carried out. It was found that the obtained solar cells based on CdTe on a flexible substrate have a high degradation resistance and after 10 bending cycles there is no decrease in the output parameters. Thus, it has been established that chemical etching in a nitrogen-phosphorus mixture is a mandatory procedure for the formation of efficient solar cells on a flexible substrate