Tuning Electronic and Optical Properties of 2D/3D Interfaces of Hybrid Perovskites through Interfacial Charge Transfer: Prediction of Higher-Efficiency Interface Solar Cells Using Hybrid-DFT Methods.

The 2D/3D or 2D/quasi-2D composite mixed-dimensional construction of hybrid perovskite interfaces is gaining increasing attention due to their enhanced stability toward degradation without compromising the corresponding solar cell efficiency. Much of this is due to the interfacial charge transfer and its consequences on the electronic and optical response of the composite system, which are instrumental in the context of stability and efficiency. In this work, we have considered a case study of an experimentally motivated 2D/quasi-2D interface constructed based on Ruddlesden-Popper phases of (A43)PbI (2D phase) and (A43)MAPbI (quasi-2D phase) hybrid perovskites to envisage the unique tuning of electronic and optical properties through the associated charge transfer using density functional theory calculations based on both generalized gradient approximation as well as hybrid functionals, including corrections for nonlocal exchange obtained from Hartree-Fock.

Electronic Structure of Oxide Interfaces: A Comparative Analysis of GdTiO3/SrTiO3 and LaAlO3/SrTiO3 Interfaces.

Emergent phases in the two-dimensional electron gas (2DEG) formed at the interface between two insulating oxides have attracted great attention in the past decade. We present ab-initio electronic structure calculations for the interface between a Mott insulator GdTiO3 (GTO) and a band insulator SrTiO3 (STO) and compare our results with those for the widely studied LaAlO3/SrTiO3 (LAO/STO) interface between two band insulators. Our GTO/STO results are in excellent agreement with experiments, but qualitatively different from LAO/STO.