Publication date: 2nd November 2020
Halide Perovskites (HaPs; having a general structural formula of ABX3; where A is the monovalent cation-methyl ammonium-MA/Cesium-Cs+, B is the lead-Pb2+ and X is the halide species-I-/Br-/Cl-) act as emerging candidates in the future optoelectronic technology with their high photo conversion efficiency (PCE) over 25%. Furthermore, HaPs demonstrate tunable bandgap, high carrier diffusion length, long carrier lifetime, low defect density, and efficient charge collection at metal electrodes beneficial for excellent device application. We report in-situ, room-temperature synthesis of methylammonium lead bromide (MAPbBr3) crystals using N-methyl formamide (NMF) as a solvent to understand their structural, electronic, and dielectric properties. The elemental analysis and improvement in the thermal stability of the synthesized MAPbBr3 crystals were examined with X-ray diffraction (XRD) and Thermo Gravimetric Analysis (TGA) analysis. Two-step thermal degradation was observed at ~3500C and ~5500C respectively. In the first step nearly 3500C, there is defragmentation of organic cation that occurs, which fragments crystals as methylamine (CH3NH2) and hydrobromic acid (HBr). In the second thermal degradation process at ~5500C, we observed complete defragmentation of the perovskite crystal structure. The optical properties of MAPbBr3 crystals depict a sharp rise in the absorbance ~ 570 nm regime which confirms the presence of direct bandgap material in the crystals. Dielectrics and electrical transport properties of these crystals were inspected using impedance spectroscopy tool for various applied AC voltages ranging from 10 mV to 500 mV. Equivalent circuits for the Nyquist plots i.e., Im(Z) vs Re (Z) were found wherein two different circuit parameters were obtained for 10-50 mV range and 100-500 mV AC voltage range respectively. Using simple capacitor frequency relation, we obtained the average relative permittivity of crystals of ~ 60.
In conclusion, the synthesized MAPbBr3 crystals showed high thermal and structural stabilities with a higher value of dielectric constant. Impedance spectroscopy measurements were performed under various applied AC voltages to optimize the AC voltage for device operation and to understand the change in electrical transport behaviors of the synthesized MAPbBr3 crystals.
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.