First-principles study on optoelectronic and transport properties of Al-based perovskites for energy applications

Abstract

Perovskites are a class of materials with a diversified combination of various properties that allow them to be used in a wide range of technologies, from solar cells and LEDs to superconductivity and enormous magneto-resistance, as well as topological insulators. Perovskites, established as promising replacements for silicon in conventional solar cells, are employed in solid-state illumination, sensing, and energy harvesting, while others, like oxide perovskites, have dielectric solid properties. Phonons and electron–phonon interactions play a significant role in materials, especially in the hybridization between Sr-p, Al-s,p, Er-s,d, and Ce-d orbitals. This hybridization is essential for understanding the energy gap and refractive index, which are crucial for fabricating optoelectronic devices. Optical spectra reveal a prominent absorption peak between 4.0 and 12.0 eV, depending on the energy gap between the hybridized bands. The Boltztrap code calculates the thermoelectric characteristics of perovskite oxides in the temperature range of 0 to 800 K. We observed that parental and doped compounds have a higher merit ZT value (0.42) and (1.45), respectively. The Seebeck coefficients of both compounds fall into the positive range of 50–800 K, indicating that they are p-type materials, and after this range, their nature changed to n-type. It is observed that materials in the high reflectivity zone have strong thermoelectric capabilities and could be useful for solar heating. The band gap tuning affects their optoelectronic capabilities, which are essential for developing extremely efficient optoelectronic/luminescent devices.