98%6876-37-5Relevant articles and documents
Self-template-directed synthesis of porous perovskite nanowires at room temperature for high-performance visible-light photodetectors
Zhuo, Sifei,Zhang, Jingfang,Shi, Yanmei,Huang, Yi,Zhang, Bin
, p. 5693 - 5696 (2015)
The unique optoelectronic properties and promising photovoltaic applications of organolead halide perovskites have driven the exploration of facile strategies to synthesize organometal halide perovskites and corresponding hybrid materials and devices. Currently, the preparation of CH3NH3PbBr3 perovskite nanowires, especially those with porous features, is still a great challenge. An efficient self-template-directed synthesis of high-quality porous CH3NH3PbBr3 perovskite nanowires in solution at room temperature using the Pb-containing precursor nanowires as both the sacrificial template and the Pb2+ source in the presence of CH3NH3Br and HBr is now presented. The initial formation of CH3NH3PbBr3 perovskite layers on the surface of the precursor nanowires and the following dissolution of the organic component of the latter led to the formation of mesopores and the preservation of the 1D morphology. Furthermore, the perovskite nanowires are potential materials for visible-light photodetectors with high sensitivity and stability. In solution: Porous CH3NH3PbBr3 perovskite nanowires (PNW-CH3NH3PbBr3) were fabricated by an efficient self-template-directed synthesis using the Pb-containing precursor nanowires as both the sacrificial template and the Pb2+ source in the presence of CH3NH3Br and HBr in solution. The perovskite nanowires are potential materials for visible-light photodetectors.
3D hybrid perovskite solid solutions: a facile approach for deposition of nanoparticles and thin films via B-site substitution
Aamir, Muhammad,Mehmood, Rana Farhat,Butt, Arshad Farooq,Khan, Malik Dilshad,Malik, Mohammad Azad,Revaprasadu, Neerish,Nunzi, Jean-Michel,Sher, Muhammad,Akhtar, Javeed
, p. 5448 - 5454 (2019)
Mixed metal halide perovskites are gaining paramount interest due to efficient band gap tenability and improved optical properties compared to their single metal halide perovskites. It is thus valuable to investigate compositional changes in lead halide perovskites to explore energy changes. Herein, we report the synthesis of a lead to lead free hybrid perovskite solid solution (CH3NH3Pb1?xCuxBr3) as nanoparticles and films. The increasing concentration of Cu2+ ions in the site of the Pb2+ ion in the perovskite shifted the diffraction peaks to a larger angle. Uniform spherically shaped nanoparticles were synthesized by a wet chemical method, the higher Cu2+ concentration leads to agglomeration, producing sheet like morphologies. However, the deposition of thin films of CH3NH3Pb1?xCuxBr3 perovskite solid solution shows that well defined morphologies begin to appear with increasing concentrations of Cu2+ in the perovskite structure. The as-prepared bulk lead free CH3NH3CuBr3 perovskite shows a band gap of 1.65 eV. A blue shift in photoluminescence (PL) was observed with copper enriched hybrid perovskites.
Novel synthesis process of methyl ammonium bromide and effect of particle size on structural, optical and thermodynamic behavior of CH3NH3PbBr3 organometallic perovskite light harvester
Singh, Rajan Kumar,Kumar, Ranveer,Kumar, Amit,Jain, Neha,Singh, Rajiv Kr.,Singh, Jai
, p. 728 - 736 (2018)
A simple, cost effective production approach having high stability is pertinent to any organic-inorganic perovskite solar cells. The main focus of the present work has been to formulate and estimate the stability of CH3NH3PbBr3 micro-cubes and nanoparticles based perovskite solar cells. Firstly, novel synthesis route has been introduced for the preparation of CH3NH3Br (MABr) electrolyte salt which is less time consuming, as well as cost effective than pristine methods. We also reported a facile single solution process to grow large scale CH3NH3PbBr3 (MAPbBr3) hybrid perovskite micro-cubes and nano-particles. The effect of different size (micro-cube & nano-particles) of perovskite material on structural, optical, thermal stability and degradation kinetics has been examined. X-ray diffraction spectra of MAPbBr3 perovskite reflect high crystallinity and cubic structure of the material at the room temperature. The surface morphology of micro-cubes and nano-particle MAPbBr3 has been obtained from scanning electron microscope (SEM). Broad absorption spectrum has found in the visible region with high absorption coefficient and PL spectra show the green emission which is in good agreement with the optical band gap of MAPbBr3 from absorption measurements. With decreasing the size of perovskite materials, band gap and emission spectra tuned towards the blue region. The simultaneous thermal analysis (STA) study indicates towards the more thermal stability of micro-cubes structures than nanoparticles material while the change in enthalpy (ΔH) and specific heat capacity (ΔCp) of nano particle have increased by reducing the particle size of perovskite due to modification of endothermic peaks.
Self-powered X-ray detector based on methylammonium lead tribromide single crystals
Xu, Qiang,Zhang, Bohao,Nie, Jing,Zhang, Hang,Ouyang, Xiaoping,Liu, Jun,Liu, Yang
, (2021)
Low-cost, high sensitivity and self-powered radiation detectors are highly demanded for photon flux detection. Here the fabrication of a self-powered X-ray detector with schottky structure is reported. Organic-inorganic perovskite CH3NH3PbBr3 single crystals have been grown on ITO glass with the solution-processed method at relatively low temperature. Low work function Ag has been deposited on the surface of the crystal to form schottky contact. The devices exhibit an obvious response to both the wavelength of 405 nm laser and X-ray photons without external bias. The achieved X-ray sensitivity is up to 2.35 × 10?4 μC μGy?1cm?2 under 35 kV X-ray exposure without bias. The results demonstrated that this schottky diode based on perovskite enable for energy-saving X-ray detection.
Enhancing performances of hybrid perovskite light emitting diodes with thickness controlled PMMA interlayer
Kumar, Gundam Sandeep,Pradhan, Bapi,Kamilya, Tapas,Acharya, Somobrata
, p. 1241 - 1248 (2018)
Solution processed organic-inorganic halide perovskites emerged as efficient materials for the fabrication of lightemitting diodes (LEDs). Spin coating of perovskites on solid support for device integration leads to poor morphology with pinholes and leakage current through electrical shunt paths thereby decreasing the device efficiency. Here, we report a facile route to improve the performance of MAPbBr3 perovskite based LEDs by incorporating a poly(methyl methacrylate) (PMMA) interlayer in the device structure at the interface of ZnO and MAPbBr33layer. The thickness of PMMA interlayer was varied to achieve optimal device performance by overcoming the leakage current and reduced non-radiative recombination pathways. LEDs with optimal PMMA thickness showed a significant enhancement in device performance comparison to the devices without PMMA interlayer. The perovskite LEDs with ～7 nm PMMA interlayer exhibit a maximum luminance of ～3450 cdm-2, current efficiency of ～11.88 cdA-1, external quantum efficiency of ～2.82% and power efficiency of ～4.4 lmW-1 showing robust LED properties with 36-fold enhancement compared to a device without PMMA. Our route provides a convenient way to improve the efficiency of perovskite LEDs by controlling device structure with planar PMMA interlayer, which can be extended to other perovskite LEDs.
Electrochemistry and Electrochemiluminescence of Organometal Halide Perovskite Nanocrystals in Aqueous Medium
Tan, Xiao,Zhang, Bin,Zou, Guizheng
, p. 8772 - 8776 (2017)
The redox nature and electrochemiluminescence (ECL) of highly crystallized organometal halide perovskite CH3NH3PbBr3 nanocrystals (NCs) in aqueous medium were investigated for the first time. CH3NH3PbBr3 NCs could be electrochemically reduced to negative charge states by injecting electrons into the lowest unoccupied molecular orbitals and oxidized to positive charge states by removing electrons from the highest occupied molecular orbitals; charge transfer between NCs with positive and negative charge states could produce ECL. The redox sequence of CH3NH3PbBr3 NCs played an important role in the generation of charge-transfer-mediated ECL; transient ECL could be achieved only by electrochemically reducing positive-charged NCs in an annihilation route. A large redox current was unfavorable for ECL. Charge mobility within CH3NH3PbBr3 NCs had an important effect on ECL intensity in a co-reactant route, which is promising for photovoltaic and optoelectronic device applications. Importantly, the ECL spectra of CH3NH3PbBr3 NCs were almost identical to their photoluminescence spectra, with a maximum emission around 535 nm and full width at half-maximum around 25 nm; this might open a way to obtaining monochromatic ECL using highly crystallized NCs as emitters, which makes them promising for use in color-selective ECL analysis.
Structural, morphological and thermodynamic parameters investigation of tunable MAPb1?xCdxBr3–2xI2x hybrid perovskite
Singh, Rajan Kumar,Sharma, Pushkal,Lu, Chung-Hsin,Kumar, Ranveer,Jain, Neha,Singh, Jai
, (2021)
Organic-inorganic hybrid perovskites are a leading successor for the next-generation electronic and optoelectronic devices, owing to their unique optical and electrical properties. There has been a concerted effort to understand how different elements can further allow us to tune these properties more favorably for different applications. Herein, we propose to tune these properties further via simultaneous cation-anion co-doping in CH3NH3PbBr3 perovskite using CdI2. We probed how the incorporation of carefully selected anionic and cationic dopants may synergically affect the perovskite properties, including the crystalline phase, thin-film morphology, optical and thermodynamic properties. We supplemented our studies with microscopy, namely SEM coupled with EDAX, to analyze the impact of double dopants on the grain size, pinhole morphology, and elemental composition of the hybrid perovskites. Spectroscopic measurements (UV–Vis–DRS and FTIR) were conducted on the hybrids to see how the interactions with Cd and I with the perovskite might additively modulate the energy band gap and functional group functionality. With the help of the simultaneous application of TGA and DSC, we were able to characterize the thermodynamic behavior (thermal stability and enthalpy change) of co-doped hybrids, which become especially important when operating at scale. This combined spectroscopic and thermodynamic study on the effects of co-doping will help to develop better algorithmic designs to choose multiple dopants which can synergically enhance desired optoelectronic properties at scale.
Collective and individual impacts of the cascade doping of alkali cations in perovskite single crystals
Huang, Yuan,Si, Rui,Sun, Junliang,Wang, Xiaoge,Zhang, Yu,Zhou, Huanping
, p. 15351 - 15360 (2020)
Alkali ion (Cs+, Rb+ and K+) incorporated hybrid perovskite polycrystalline films have shown great potential for obtaining highly efficient and stable perovskite solar cells. A study on the intrinsic influence of different alkali ions on perovskites is urgently needed to gain insights into the optoelectronic performance improvement. Single crystals with fewer defects can be ideal candidates for the study of intrinsic properties. Herein, for the first time, we prepared a series of perovskite (FA0.85MA0.15PbI2.55Br0.45) single crystals with Cs+, Rb+, and K+ cascade doping using the inverse temperature crystallization method and systematically characterized their structure and optoelectronic properties, as well as phase, humidity and thermal stability. Our work highlights the structure-property relationship, that is, diversified A-site occupation (especially the FAMACsRb system) can significantly promote the carrier transport behavior of perovskites, as well as achieving better thermal and humidity stability, while K+ doping degrades the intrinsic properties of perovskites, which is probably due to the interstitial occupation of K+. These findings deepen the understanding of the influence of alkali ion doping on the intrinsic properties of perovskite materials, which will provide an exemplary paradigm for further exploration. This journal is
High efficiency and stable photoluminescence of CH3NH3PbBr3@CsPbBr3perovskite quantum dots
Wang, Yajing,Li, Ahui,Hu, Yizhen,Bao, Yanping,Zhang, Yongfan,Hu, Xiaolin,Zhuang, Naifeng
, p. 1356 - 1359 (2021/02/22)
CH3NH3PbBr3@CsPbBr3quantum dots were prepared by epitaxially growing a CsPbBr3shell on the surface of CH3NH3PbBr3due to their similar crystal structures. The inorganic CsPbBr3shell provides enhanced stability for the CH3NH3PbBr3core. Compared with that of CH3NH3PbBr3, the photoluminescence of CH3NH3PbBr3@CsPbBr3quantum dots is not only strong, but also stable for months, in addition to having a high quantum yield.
