Density Functional Theory Calculations of Optoelectronic Properties of Individual and Encapsulated Magnesium Porphyrin in Carbon Nanotubes for Organic Nanohybrid Solar Cells

This research discusses incorporating a single magnesium porphyrin molecule into a semiconducting single-walled carbon nanotube (SWCNT) for solar cell applications. Using density functional theory (DFT), the study examines the optical and electronic properties of the isolated magnesium porphyrin molecule and two configurations of the hybrid system. Results show structural stability due to charge transfer between the molecule and the nanotube. Different exchange-correlation functionals (GGA and HSE06) yield varied bandgap results, affecting light absorption. Integration of the molecule into the SWCNT reduces the bandgap. Encapsulation of the molecule influences absorption and stability under irradiation. These encapsulated systems exhibit type II heterojunction characteristics, making them promising for organic solar cells based on SWCNTs, offering potential for highly efficient solar cells. The charge transfer mechanism and its direction in the hybrids illustrate that the increased Fermi energy of SWNT17 postencapsulation results in a CT connection from the magnesium porphyrin molecule (as donor) to SWNT17 (as acceptor), suggesting that the hybrids contain type-II band alignment.image (c) 2024 WILEY-VCH GmbH