As climate change continues to be the most pressing threat facing our planet, researchers strive to find efficient and clean alternatives to fossil fuels. The most important thing in this research is the use of free energy from the sun. Doing this effectively requires a solid understanding of the quality of the materials used in the solar cell structure.
published in EPJ PlusMaykel Courel from the Central University of Guadalajara (CUValles) in Mexico and co-authors investigated the limitations of the material sulfide selenide, which has emerged as a potential candidate for solar cell fabrication.
The semiconductor antimony selenide sulfide has been intensively studied by researchers studying thin-film solar cells due to the fact that the material has a high absorption coefficient due to direct optical transitions. However, the material’s use in devices that use semiconductor materials to convert light into electricity is still in its early stages.
Currently, the material’s efficiency peaks at around 10 percent, well below 29 percent, the maximum efficiency expected for this type of technology.
The researchers set out to test the limiting factors affecting this efficiency, focusing on the effect of loss mechanisms on antimony selenide sulfide batteries using analytical models.
The team found that, for the typical parameters chosen for their simulations, electron-hole recombination in the substrate (called bulk recombination) and interfacial recombination that occurs when the two semiconductor band gaps take on a staggered shape are the main problems that degrade device performance.
They argue that materials scientists working to reduce interfacial or bulk defects in antimony sulfide diselenide devices will not be able to achieve efficiencies greater than 10 percent. On the other hand, when the carrier lifetime exceeds 100 nanoseconds and the recombination velocity is below 1 centimeter per second, the efficiency of this technique can be as high as 14%.