Open AccessTheoretical study of spectral responses of heterojunctions based on CuInSe2 and CuInS2
Author(s) -
El-Hadji Mamadou Keita,
Bara Ndiaye,
M. Dia,
Yousef Rezaei Tabar,
C. Sène,
B. Mbow
Publication year - 2020
Publication title -
materials and devices
Language(s) - English
Resource type - Journals
ISSN - 2495-3911
DOI - 10.23647/ca.md202005
Subject(s) - heterojunction , substrate (aquarium) , band diagram , diffusion , photocurrent , materials science , semiconductor , base (topology) , layer (electronics) , optoelectronics , electronic band structure , condensed matter physics , nanotechnology , physics , mathematics , thermodynamics , mathematical analysis , oceanography , geology
In this work we study the spectral responses of thin films solar cells of heterojunctions based on CuInSe2 and CuInS2. Four-layer structures are studied according to the n+n/pp+ model. First we consider the structure ZnO(n+)/CdS(n)/CuInS2(p)/CuInSe2(p+) where CuInS2 represent the base and CuInSe2 the substrate in this model. Secondly we consider the structure ZnO(n+)/CdS(n)/CuInSe2(p)/ CuInS2(p+), for this model CuInSe2 represent the base and CuInS2 the substrate. ZnO and CdS are used as window layers in each structure. Using the continuity equation that governs transport of carriers in semiconductor material, models for calculating spectral responses are proposed for heterojunctions type n+n/pp+ based on CuInSe2 and CuInS2. For each structure we have presented the energy band diagram based on the Anderson model [1] and determined the expression of the photocurrent. The theoretical results obtained allow to compare the performances of these two models by optimizing the different parameters of each structure (base thickness, diffusion length, recombination velocity at the interface, etc.) in order to improve the overall efficiency of the collection of carriers.