| Work Detail |
A group of researchers has once again tried to design solar cells based on non-toxic and abundant copper and antimony sulfide on Earth. The proposed cell architecture is the result of optimizing the thickness of the device layers.
Researchers led by Kenyas Masinde Muliro University of Science and Technology have designed a solar cell with an absorber based on copper antimony sulfide (CuSbS2), which is a non-toxic and abundant semiconductor material on Earth with promising prospects in photovoltaics. due to its high absorption coefficient and adequate bandgap.
The scientists numerically simulated and optimized the solar cell using SCAPS-1D solar cell capacitance software, a thin-film solar cell simulation tool developed by Ghent University, Belgium.
The solar cell was designed with a transparent fluorine-doped tin oxide (FTO) glass substrate, a cadmium sulfide (CdS)-based hole transport layer (HTL), the CuSbS2 absorber, an electron transport layer (ETL) made with carbon (C) and a gold (Au) metal contact.
FTO and CuSbS2 have an energy bandgap of 3.5 eV and 1.5 eV, respectively, while for CdS and C these values ??are 2.42 eV and 3 V, respectively.
“Cadmium sulfide was used as an electron transport layer to prevent the holes from reaching frontal contact,” the researchers explain. “FTO was preferred to ITO because it has special characteristics of chemical inertness, when heated it is stable, mechanically hard, a good conductor, relatively cheap and its sheet resistance remains constant during sintering.”
To optimize the device, the academics investigated different thicknesses of FTO, CdS, C, CuSbS2, as well as the concentration of defects and dopants in the absorber. They found that the FTO had to be 100 nm thick. Furthermore, they determined that CdS, CuSbS2 and C should have a thickness of 50 nm, 300 nm and 100 nm, respectively.
The optimized cell achieved a power conversion efficiency of 16.17%, an open circuit voltage of 0.9389 V, a short circuit current density of 28.32 mA/cm2 and a fill factor of 60.8%.
“The variation of the dopant concentration revealed that an increase in the dopant concentration led to an increase in the efficiency of the photovoltaic cell,” they explained. “The increase in defect density led to a decrease in diffusion length, indicating an increase in the recombination rate.”
The new cell concept was presented in the published article “ Numerical study of copper antimony sulphide (CuSbS2) solar cell by SCAPS-1D ” in Heliyon . |
