Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 24: Hybrid and Perovskite Photovoltaics III
CPP 24.5: Vortrag
Mittwoch, 19. März 2025, 10:30–10:45, H38
First-principles modelling of hybrid perovskites — •Udo Schwingenschlögl and Aleksandra Oranskaia — King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
The photoconversion efficiency record of silicon-perovskite solar cells exceeds 30% owing to hybrid perovskites with organic cations that stabilize the perovskite by non-covalent bonding. To address the electronic properties and stability issue from the perspectives of the bulk crystal phases, point defects, and surfaces and interfaces (requiring large simulation cells) the computational methods must be chosen carefully: (1) For the structural relaxation an exchange-correlation functional is required that adequately describes materials rich in NH⋯I bonding (between organic cations and I) and I⋯I bonding (between PbI6 octahedra or between PbI6 octahedra and I-related defects). (2) For the electronic structure calculation an exchange-correlation functional is required that adequately describes the spin-orbit coupling of the Pb and I electrons. Comparing the PBE, PBE-TS, PBE-D3, PBEsol, vdW-DF2, and rVV10 functionals for relaxing FAI, C4N2H12(I3)2, C6H7NI(I3), I2, In, Cs(I3), Cs2(I3)2(I2), and PbI2 crystals, we show that the rVV10 functional provides the most balanced prediction for the types of non-covalent bonding relevant for hybrid perovskites. We also discuss problems related to the HSE06 functional and show that the PBE functional with a Hubbard correction for the Pb 6p and I 5p orbitals (together with fully relativistic pseudopotentials) provides promising results.