Proceedings of 6th International Conference on Hybrid and Organic Photovoltaics (HOPV14)
Publication date: 1st March 2014
Recently the use of soluble semiconductors such as organic-inorganic perovskites has shown great promise as light absorbers in solid state mesoscopic solar cells. A functioning solar cell requires well aligned energy levels in the different materials: the light absorber, the supporting mesoporous oxide and the hole conductor. A key question in the development of perovskite materials is thus the understanding of the electronic structure and energy level matching at the different interfaces. In this study, we use photoelectron spectroscopic techniques to experimentally study such properties of perovskite films deposited onto mesoporous oxides.
Photoelectron spectroscopy with hard X-rays (HAXPES) can be used to study buried interfaces in a non-destructive way. It is therefore possible to directly measure the occupied energy levels of the perovskite as well as the TiO2 buried beneath, and thereby receive a direct measurement of energy level matching of the interface. The study involves measurements of the electronic structure and chemical composition of different perovskite materials where the halide or the organic cation have been varied (for example CH3NH3PbI3 and CH3NH3PbBr3). Experimental results are also compared to theoretically calculated density of states (DOS) using density functional theory (DFT).
We show that two different deposition techniques of the TiO2/CH3NH3PbI3 interface give results indicating similar electronic structures. Especially a similar binding energy of the valence band edge gives similar energy level matching in a solar cell. Simulated DOS of the valence structure describes the experimental spectra very well and shows that the outermost levels consist of lead and iodine orbitals. Due to a relatively higher cross section at high photon energies for heavier elements, HAXPES is therefore very useful to study the position as well as the orbital character of the valence band edge. [1]
[1] R. Lindblad, D. Bi, B.-w. Park, J. Oscarsson, M. Gorgoi, H. Siegbahn, M. Odelius, E. M. J. Johansson and H. Resmo, J. Phys. Chem. Lett., http://dx.doi.org/10.1021/jz402749f
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.