Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV22)
DOI: https://doi.org/10.29363/nanoge.hopv.2022.155
Publication date: 20th April 2022
Lead halide perovskites are considered one of the largest breakthroughs in the optoelectronic research field in recent years due to their versatility and their multiple applications including solar cells, LEDs and X-ray detectors among others. All perovskite based optoelectronic devices are made by contacting different materials to the perovskite itself. Therefore, a detailed understanding of the surface and interface properties of lead halide perovskites is crucial for creating more stable and efficient devices. Due to the difficulty of obtaining clean perovskite surfaces for study, up to date, most of surface research was done theoretically. It is worth to note that some experimental studies have been carried out on cleaved surfaces of single crystals, but most of these have focussed on ARPES and STM. [1-3]
In our work, we investigate the surface properties and electronic structure of in-situ cleaved perovskite single crystals with photoelectron spectroscopy at the FlexPES beamline at MAX IV.[4] The use of synchrotron-based soft X-ray photoelectron spectroscopy enables high surface sensitivity and nondestructive depth-profiling. We present a detailed core level and valence band analysis of methylammonium lead triiodide (MAPbI3) and cesium doped formamidinium lead triiodide (CsxFA1-xPbI3). Additionally, we can distinguish two carbon 1s contributions at the surface of MAPbI3. With support of density functional theory and molecular dynamics simulations, we can assign these to MA+ ions in an MAI-terminated surface and to MA+ ions below the surface. We estimate that the surface is predominantly MAI-terminated but up to 30% of the surface could be PbI2-terminated. Our results can be used to optimize future perovskite-based device interfaces and our measurements can be used as a reference for future photoelectron spectroscopy investigations on hybrid perovskite materials.
The authors acknowledge funding from the Swedish Research Council (Grant Nos. VR 2018-04125, VR 2018-06465 and VR 2018-04330), the Göran Gustafsson Foundation, the Swedish Foundation for Strategic Research (Project No. RMA15-0130), and the Carl Tryggers Foundation (Grant No. CTS 18:59). The authors acknowledge MAX IV Laboratory for time on Beamline FlexPES under proposal 20200451. Research conducted at MAX IV, a Swedish national user facility, was supported by the Swedish Research Council under contract 2018-07152, the Swedish Governmental Agency for Innovation Systems under contract 2018- 04969, and Formas under contract 2019-02496. The authors also thank Stephan Appelfeller, Alexei Preobrajenski, and Alexander Generalov for support during the FlexPES beamtime. M.O. acknowledges support from the Swedish Energy Agency (Grant No. 2017-006797). The calculations were enabled by resources provided by the Swedish National Infrastructure for Computing (SNIC), partially funded by the Swedish Research Council through Grant Agreement No. 2018-05973.
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.
nanoGe Fall Meeting (NFM) is a multiple symposia conference celebrated yearly and 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.
This conference is a unique series of symposia focused on advanced materials preparation and fundamental properties and their applications, in fields such as renewable energy (photovoltaics, batteries), lighting, semiconductor quantum dots, 2-D materials synthesis and semiconductors fundamentals, bioimaging, 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.