Proceedings of International Conference on Perovskite Thin Film Photovoltaics and Perovskite Photonics and Optoelectronics (NIPHO20)
DOI: https://doi.org/10.29363/nanoge.nipho.2020.009
Publication date: 25th November 2019
Organic-inorganic perovskites are one of the most promising material classes for photovoltaic applications, since the achieved efficiency increased during the last 10 years from 3.8% to over 24% [1,2].While most of the research groups are working on the device efficiency and stability enhancement, there is still a lack of understanding and experimental validation of the influence of trap states on the perovskite charge carrier transport and especially the recombination properties. Besides the radiative and Auger recombinations, which relate to intrinsic recombination processes, the trap-assisted Shockley-Reed-Hall (SRH) and interface recombination play a critical role for the efficiency of perovskite solar cells. Therefore, here we experimentally investigate the energetic distribution of perovskite bulk and metal interface states on the example of methylammonium lead iodide (MAPI) thin-films.
For this purpose we use the thermally stimulated current (TSC) method. To avoid the well-known disadvantages of classical TSC, such as the recombination of complementary charge carriers and high leakage currents, we have recently introduced a modification of this method, by using a metal-insulator-semiconductor (MIS) sample structure for the TSC experiment (MIS-TSC)[3]. The use of the MIS structure allows for a true unipolar high-resolution trap state evaluation, low leakage currents (jleakage< 1 fA/cm2), and avoids charge carrier recombination due to unipolar trap filling.
To distinguish between defect states in the perovskite bulk and metal-induced interface trap states, we have investigated devices using different metals (Ag, Au and Ni) as top contacts. We detect characteristic trap states independent of the contact metallization, which are probably related to the defect states in the perovskite bulk and are in line with the current literature. We demonstrate further, that the type of top metallizations strongly influences trap states at the MAPI/metal interface. While the formation of hole and electron trap states with low activation energy was observed for Ag contacts, the formation of deeper trap states in the range of 400 meV for electrons and 1400 meV for holes was detected for MAPI/Au and MAPI/Ni interfaces.
The authors acknowledge financial support through the European Union in the Leitmarktwettbewerb NRW: Neue Werkstoffe, within the PeroBOOST project (EFRE-0800120; NW-1-1-040).
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.