In this paper we propose to study the performances of thin films solar cells based on CuInSe2. The following models are studied : p/n ; p+/p/n ; p/n/n+; p+/p/n/n+. The objective of this work is to study the performance of the homojunction based on CuInSe2, with a medium band gap window layer based on CuInS2, deposited on a substrate, according to the model CuInS2(p+)/CuInSe2(p)/CuInSe2(n)/CuInSe2(n+) (p+/p/n/n+). We compare this structure (p+/p/n/n+) with the following models: the homojunction CuInSe2(p)/CuInSe2(n) (p/n), the homojonction with window layer CuInS2(p+)/CuInSe2(p)/CuInSe2(n) (p/n/n+) and the homojunction deposited on substrate CuInSe2(p)/CuInSe2(n)/ CuInSe2(n+) (p/n/n+). Calculation models for determining the density of the minority carriers, the density of the photocurrent, and the internal quantum efficiency were established for the different structures. These theoretical results are used to compare their performance. In order to test the validity of our calculations models, We compare our results with some experimental results published in the literature
