Regensburg 2016 – scientific programme
CPP 31.6: Talk
Wednesday, March 9, 2016, 11:00–11:15, H11
XPS study of the ALD growth of Al2O3 on the CH3NH3PbI3 — •Małgorzata Sowińska1, Chittaranjan Das1, Konrad Wojciechowski2, Henry Snaith2, and Dieter Schmeisser1 — 1Brandenburgische Technische Universität Cottbus-Senftenberg, Angewandte Physik-Sensorik, Konrad-Wachsmann-Allee 17, 03046 Cottbus, Germany — 2Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX13PU, UK
Organic-inorganic lead halide perovskites have emerged as very attractive absorber materials for the fabrication of low cost and high efficiency solar cells, but a delicate nature of these films is one of the main challenges for a successful commercialization. Typically, when exposed to air or moisture, perovskite films degrade within a couple of hours or days. Moreover, the methylammonium lead triiodide (CH3NH3PbI3) perovskite cannot sustain a prolonged annealing at temperatures around 85∘C. In this work, we are investigating stability (upon air and thermal exposure) of a CH3NH3PbI3 perovskite film coated with a thin layer of Al2O3 deposited by atomic layer deposition (ALD). In particular, the chemical and electronic changes occurred at the Al2O3/CH3NH3PbI3 interface during the first 50 ALD cycles were monitored ex-situ by high-resolution and surface-sensitive synchrotron-based X-ray photoelectron spectroscopy (SR-XPS). The advantage of the ALD as a deposition method is that it can produce extremely dense layers with a very precise thickness control at room temperature. Detailed SR-XPS data analysis and a stability test of the perovskite film with alumina will be presented.