Band alignment and charge transfer in rutile-TiO2/CH3NH3PbI3-xClx interfaces.
Rutile-TiO2/hybrid halide perovskite CH3NH3PbI3-xClx interfaces are investigated by ab initio density functional theory calculations. The role of chlorine in achieving enhanced solar cell power conversion efficiencies is in the focus of recent studies, which point to increased carrier mobilities, reduced recombination rates, a driven morphology evolution of the perovskite layer and improved carrier transport across the interface. As it was recently established that chlorine is preferentially localized in the vicinity of the interface and not in the bulk of the perovskite layer, we analyze the changes introduced in the electronic properties by varying the chlorine concentration near the interface. In particular, we discuss the effects introduced in the electronic band structure and show the role of chlorine in the enhanced electron injection into the rutile-TiO2 layer. Taking into account these implications, we discuss the conditions for optimizing the solar cell efficiency in terms of interfacial chlorine concentration.
University of Bucharest, Faculty of Physics, Materials and Devices for Electronics and Optoelectronics Research Center, P.O. Box MG-11, 077125 Magurele-Ilfov, Romania. nemnes@solid.fizica.unibuc.ro.
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Nemnes
School of Science and Engineering, Reykjavik University, Menntavegur 1, IS-101 Reykjavik, Iceland.
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Goehry
University of Bucharest, Faculty of Physics, Materials and Devices for Electronics and Optoelectronics Research Center, P.O. Box MG-11, 077125 Magurele-Ilfov, Romania. nemnes@solid.fizica.unibuc.ro.
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Mitran
University of Bucharest, Faculty of Physics, Materials and Devices for Electronics and Optoelectronics Research Center, P.O. Box MG-11, 077125 Magurele-Ilfov, Romania. nemnes@solid.fizica.unibuc.ro.
Adela
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Nicolaev
University of Bucharest, Faculty of Physics, Materials and Devices for Electronics and Optoelectronics Research Center, P.O. Box MG-11, 077125 Magurele-Ilfov, Romania. nemnes@solid.fizica.unibuc.ro.
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Ion
University of Bucharest, Faculty of Physics, Materials and Devices for Electronics and Optoelectronics Research Center, P.O. Box MG-11, 077125 Magurele-Ilfov, Romania. nemnes@solid.fizica.unibuc.ro.
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Antohe
Natl Inst Mat Phys, Magurele 077125, Ilfov, Romania.
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Plugaru
School of Science and Engineering, Reykjavik University, Menntavegur 1, IS-101 Reykjavik, Iceland.
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Manolescu