A Comprehensive Approach Toward Achieving High-Efficiency CTGSSe-Based Solar Cells

This work presents a comprehensive exploration of Cu
₂
(Sn,Ge)(S,Se)
₃
(CTGSSe) thin-film solar cells, encompassing deposition techniques, material characterization, device simulations, and performance evaluations. Initial investigations focus on the deposition of CTGSSe thin films over soda-lime glass (SLG) substrates utilizing a dual-ion beam sputtering (DIBS) system. The deposited films exhibit desirable optical properties with a bandgap (
${E} _{\text {g}}$
) of ~1.48 eV, high absorption coefficient (
$\alpha $
) of the order of
$10^{{5}}$
cm
$^{-{1}}$
, and high hole mobility of 54.12 cm
$^{{2}}\cdot \text {V}^{-{1}}\cdot \text {s}^{-{1}}$
along with stable p-type character- istics as confirmed by hall measurements, laying the foundation for subsequent device analysis. The experi- mental parameters and the absorption profile thus obtai- ned are incorporated into the proposed Al/Ga:ZnO/ CdS/CTGSSe/Mo device simulations using the solar cell capacitance simulator (SCAPS) tool to assess the performance parameters of CTGSSe solar cells. Additionally, the device modeling results demonstrate a
${V} _{\text {oc}}$
of 0.466 V,
${J} _{\text {sc}}$
as 27.845 mA/cm
²
, FF =59.21%, and promising power conversion efficiency (PCE) of 7.68% under standard AM 1.5 G solar spectrum conditions, which can be further improved to 10.06% by substituting toxic CdS with nontoxic, abundant, and sustainable SnS
₂
as the buffer layer.