A group of researchers from The Autonomous University of Querétaro in Mexico has developed a new type of perovskite solar cells with high efficiency and environmental friendliness.
With the advent of of lead-halide perovskite solar cells was achieved for the first time performance indicators solar energy conversion of 25-29%. However, a number of problems, including instability, vulnerability to heat, light, and moisture, and lead toxicity, have prevented the technology from scaling up. To overcome these limitations, researchers from Mexico have proposed chalcogenide perovskites, in particular, SrHfSe3 , providing chemical stability, light absorption capacity «setting», high photon absorption coefficient and increased mobility of p-type positive charges.
The new solar cell was created from several layers of different materials. Initially, molybdenite was chosen as one of the layers for conducting current. In addition to it, another 40 different materials were tested, ranging from classical semiconductors to state-of-the-art nanofilms.
In the study, the researchers used the SCAPS-1D modeling tool developed by Mark Burgelman, a scientist at Ghent University, and simulated 1627 variations of solar cells under conditions as close to real-world conditions as possible. The scientists tried to optimize key parameters as much as possible, such as density of absorber acceptors, defect density, thickness, and back contact operating functions. Optimizations led to improvements in light absorption, minimizing recombination losses, increasing the built-in potential and improving charge transfer characteristics.
Among the modeled configurations, three materials demonstrated the highest efficiency as conductive layers: SnS, CPE-K, and Ti2 CO2 , achieving efficiency of 27.87%, 27.39% and 26.30%, respectively.
The researchers explain that the improvements were primarily due to higher short-circuit current densities, increased quasi-Fermi level splitting, improved carrier generation, stronger internal electric fields, improved QE and diffusion length. The scientists emphasize that they offer a reliable, stable and, most importantly, environmentally friendly alternative to conventional perovskites.
The results of the study are published in the journal Solar Energy Materials and Solar Cells
Source: TechXplore