Enhancing the performance of quantum dot solar cells through halogen adatoms on carboxyl edge-functionalized graphene quantum dots

Abstract

This research has been conducted to find new, high-performing, safe, and suitable materials for use in quantum dot solar cells (QDSCs). Specifically, impact of halogen adatoms (Br, Cl, and F) on carboxyl edge-functionalized graphene quantum dot (CO2H-GQD) has been investigated employing DFT-based first-principles computations. We analyzed energy gaps (Eg), LUMO, and HOMO to determine how the foreign atom affects electronic features of material, employing hybrid functional B3LYP with a 6-31G basis set. In order to investigate charge separation and electron injection in both doped and undoped CO2H-GQD, we examined charge transfer (CT), molecular electrostatic potential (MESP), and binding mechanism. Optical attributes also indicate a wide spectrum in visible range, making it suitable for harvesting solar light. Furthermore, we evaluated solar cell parameters, including efficiency (η), short circuit current density (Jsc), fill factor (FF), and open circuit voltage (Voc) to assess potential usage of adatom-doped CO2H-GQD in quantum dot solar cell. Subsequent to Br, Cl, and F substitutional doping, value of η for CO2H-GQD increased. In case of F doping, we achieved maximum η, which has electron-donating nature and a larger radius, allowing it to inject more electrons into titanium dioxide (TiO2) surface. Based on our research, we have determined that these recently discovered sensitizers built upon GQD exhibit considerable potential for use in QDSCs.