Proceedings of International Conference on Perovskite Thin Film Photovoltaics, Photonics and Optoelectronics (ABXPV18PEROPTO)
Publication date: 11th December 2017
Electrical hysteresis in devices based on hybrid perovskites is currently attributed to the migration of charged species in the material, and passivation at the interfaces between active layers is proposed as a way to suppress the phenomenon. Based on electron paramagnetic resonance (EPR) measurements, we highlight the fundamental role of carbon residues in suppressing hysteresis in ligand-free, laser-ablated CH3NH3PbI3 nanoparticles.[1]
PbI2 nanoparticles were synthesized by laser ablation of PbI2 targets in an organic solvent and subsequently converted into CH3NH3PbI3 by addition of CH3NH3I.[1] Carbonaceous residues formed during the ablation process were observed both in PbI2 and CH3NH3PbI3 samples. The electric behavior of the materials strongly depends on the nature of the solvent used during ablation, which is reflected in the nature of the residues. Hysteresis is inhibited only in the case of ablation from aromatic solvents, forming “graphene-like” residues exhibiting a significant amount of paramagnetic defects (localized unpaired electrons). EPR measurements under illumination revealed a charge transfer between the “graphene-like” component and PbI2 or CH3NH3PbI3, with subsequent trapping of the charge carriers into defect sites of the carbonaceous phase.
The system appears to work as a donor-acceptor couple: the carbon material acts as photoabsorber, but relies on the other semiconductor (CH3NH3PbI3) to allow charge separation and eventually charge trapping. Such a mechanism, resulting in trapping of charge carriers near the interface with CH3NH3PbI3, is reasonably responsible for the passivating effect involved in the suppression of hysteresis in a way similar to other carbon-based materials, i.e. fullerene derivatives, commonly used to induce passivation. [2]
[1] F. Lamberti et al., Adv. Energy Mater. 7, 1601703 (2017)
[2] Y. Shao et al., Nature Commun. 5, 5784 (2014)
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.