Simulation of the Effects of the Thickness and the Bandgap of the Absorber on the Performance of the Quaternary Thin Film Solar Cell Based on Cu(In,Ga)Se2

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Résumé

In the field of energy transformation, the share of renewable energies continues to grow and gives hope to fight against global
warming. In the global electricity mix we have: 15% for hydropower, and 14.5% for other renewables, according to 2022 figures.
Among renewable energies, photovoltaic (PV) solar energy is the most promising with very high record yields of around 29%
theoretically, 27.3% experimentally for record-breaking PV solar cells in the laboratory and 22% in industrial production for a
solar panel. The selenide, gallium, indium and copper (CIGS) sector is very promising, one of its major advantages coming that
the fact the quaternary alloy Cu(In,Ga)Se2 is a material with an adjustable bandgap (Eg). The freely available and highly stable
one-dimensional solar cell capacities simulation software, is the tool used for the simulation. Digital simulation is an essential
tool because it makes it possible to predict the behavior of the solar device and to be able to estimate its performances. The study
of effects of the thickness (WCIGS) and the gap of the CIGS absorber with a cadmium sulfide buffer layer of 30 nm shows that
current-voltage density characteristic is enormously affected for WCIGS ≤1000 nm. We therefore note a significant decrease in
the values of the short-circuit current density (JSC) and the open-circuit voltage (VOC) when WCIGS decreases. These results are
explained by a significant reduction in the quantity of incident photons absorbed and an increase in the recombination rate of the
charge carriers photogenerated in the absorber. VOC increases and JSC decreases with the increasing of the absorber gap, the
increase in VOC is therefore linked to a significant reduction in the recombination rate at the CIGS/Mo interface and inside the
space charge region. The maximum efficiency is 26.33% for Eg = 1.45 eV and WCIGS = 3000 nm.

Mots-clés

Numerical Simulation, Quaternary Thin Film Solar, Cu(In, Ga)Se2 Absorber, Thickness, Bandgap, Electricals Parameter