Excitonic effects due to electron-hole coupling play a fundamental role in renormalizing energy levels in dye sensitized and organic solar cells determining the driving force for electron extraction. We show that first-principles calculations based on many-body perturbation theory within the GW-BSE approach provide a quantitative picture of interfacial excited state energetics in organic dye-sensitized TiO2, delivering a general rule for evaluating relevant energy levels. To perform GW-BSE calculations in such large systems we introduce a scheme based on maximally localized Wannier' s functions. With this method the overall scaling of GW-BSE calculations is reduced from O(N4) to O(N3).
Large-scale GW -BSE calculations with N3 scaling: Excitonic effects in dye-sensitized solar cells
Mosconi E.;De Angelis F.;
2017
Abstract
Excitonic effects due to electron-hole coupling play a fundamental role in renormalizing energy levels in dye sensitized and organic solar cells determining the driving force for electron extraction. We show that first-principles calculations based on many-body perturbation theory within the GW-BSE approach provide a quantitative picture of interfacial excited state energetics in organic dye-sensitized TiO2, delivering a general rule for evaluating relevant energy levels. To perform GW-BSE calculations in such large systems we introduce a scheme based on maximally localized Wannier' s functions. With this method the overall scaling of GW-BSE calculations is reduced from O(N4) to O(N3).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
