Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV16)
Publication date: 28th March 2016
The remarkable power conversion efficiency of halide perovskite solar cells has brought these materials to the frontier of photovoltaic research. However, it is necessary to overcome obstacles such as the unstable photovoltaic performance before bringing them to market. Understanding the link between performance and defect distribution, will allow scientists and engineers to design more efficient and stable perovskite optoelectronic devices. In this work we report reversible changes in photoluminescence (PL) intensity of various halide perovskites that depends on the local electric field and bias history. Further, we correlate the spatially resolved PL variations of these crystals with local compositional changes due to ionic migration, connecting performance with defect distribution.
As a model system, we study thin single microcrystals of a hybrid organic-inorganic halide perovskite (CH3NH3PbBr3) and its all-inorganic counterpart (CsPbBr3). These crystals are made from solution by a PDMS-stamping technique. Unlike the macroscopic crystals grown via slow crystallization, the thicknesses of single microcrystals made by this technique (from hundreds of nanometers up to several microns) are comparable to those of perovskite films in optoelectronic devices. Moreover, these crystals are deposited rapidly from solution, which likely makes their defect density similar to that of spin-coated films, making them ideal for studying defect-related transport phenomena.
Photovoltaic devices were made from these single-crystal perovskites using a back-contacted platform that leaves the surface of the crystals open to optical characterization while the device operates as a solar cell. Spatially resolved PL maps of these devices are obtained in short circuit or under electrical bias. These maps show that local emission intensity changes when the perovskite crystals are in an electric field. More interestingly, these variations remain even after removal of the field, indicating that they are caused by more than a simple redistribution of free charges under bias: rather, a slower process such as ionic migration is responsible for this PL hysteresis, which depends on the electrical history of the device. Spatially resolved chemical information correlates the PL intensity variations directly to the local compositional changes within the crystals induced by the applied electric field.
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.