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.
Understanding the origin of broad-band emission in CH3NH3PbBr3
Nandi, Pronoy,Giri, Chandan,Topwal, Dinesh
, p. 2793 - 2800 (2021)
Broad-band emissions related to self-trapped excitons (STEs) in the sub-bandgap region in organic-inorganic hybrid perovskites and double perovskite crystals have drawn attention in recent times due to their potential in optoelectronic device applications. In this study, we have shown that the formation of STEs in CH3NH3PbBr3single crystals can be controlled using a suitable sample synthesis procedure. We have observed a broad-band emission (FWHM ～ 80 nm) for crystals whose crystallization is fast, whereas it was absent if we follow slow crystallization procedures. Using UV-Visible absorption spectroscopy, temperature-dependent photoluminescence (PL), time-resolved PL (TRPL), and dc magnetization studies, we concluded that defect-assisted extrinsic self-trapping is dominant here over the intrinsic self-trapping process and excess Pb atoms in interstitial positions are predominantly responsible for the extrinsic self-trapping process.
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.
Stable fluorescent NH3 sensor based on MAPbBr3 encapsulated by tetrabutylammonium cations
Cheng, Ya,Chu, Junhao,Jia, Shicheng,Jing, Chengbin,Li, Guishun,Liu, Shaohua,She, Changkun,Yue, Fangyu,Zhang, Wenqian
, (2020)
Recently, organic-inorganic halide perovskite materials were investigated on gas sensing due to their excellent optical properties and gas sensitivities. Here, we designed a stable fluorescent perovskite-based sensor for NH3 detection, in which the CH3NH3PbBr3 (MAPbBr3) film was deposited on the GeO2 substrate and also capped by tetrabutylammonium (TBA) ligand as a stabilizing agent. This as-fabricated MAPbBr3-TBA-based sensor exhibited the relatively strong and stable photoluminescence (PL) intensity, thereby expanding the fluorescence response range for NH3 sensing. Upon exposure to NH3 gas, the PL intensity quenched rapidly by 62.5% with short response time (61 s) and recovery time (65 s). The sensor also possessed a linear relationship between the PL intensity and concentration of NH3 in the range of 0–100 ppm, and presented excellent reversibility, high gas selectivity, and humidity stability. Furthermore, the NH3 sensing mechanism was investigated based on X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Differential thermal analysis-Thermogravimetry (DTA-TG) and fluorescence lifetime measurements, in which the NH3 molecules might permeate the capped TBA ligand and then induce structure transformation of inner MAPbBr3 crystal. This study indicated that the as-prepared MAPbBr3-TBA-based sensor might provide promising applications on NH3 gas detection.
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.
Single-Source Thermal Ablation of halide perovskites, limitations and opportunities: The lesson of MAPbBr3
Calestani, Davide,Ferro, Patrizia,Fracassi, Francesco,Listorti, Andrea,Mezzadri, Francesco,Mosca, Roberto,Nasi, Lucia
, (2021)
Single-Source Thermal Ablation (SSTA) is a vacuum-based evaporation method that was only minorly employed in the preparation of hybrid perovskite materials for solar cells despite some promising early achievements. We study the preparation of MAPbBr3 films, showing that this material does not allow the reproducible preparation of thin films suitable for integration in multijunction devices due to the low adhesion of MABr to the substrate, on one hand, and to the proximity of decomposition and melting temperatures of MAPbBr3 combined with the high vapor pressure of MABr on the other. Based on the insights obtained on MAPbBr3 processing we demonstrate that, conversely, homogeneous fully-inorganic CsPbI2Br thin films can be prepared by SSTA with a stability comparable to that reported for films obtained by spin coating. This work provides guidelines for the selection of halide perovskites that can be successfully prepared by SSTA for thin film application.
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.
Transfer of Chiral Information from Silica Hosts to Achiral Luminescent Guests: a Simple Approach to Accessing Circularly Polarized Luminescent Systems
Tsunega, Seiji,Jin, Ren-Hua,Nakashima, Takuya,Kawai, Tsuyoshi
, p. 619 - 626 (2020)
Systems that show circularly polarized luminescence (CPL) are usually constructed in one of two possible ways: either covalently binding the chiral moieties (usually organic compounds) to luminophores (inorganic or organic compounds) or associating the luminophores as guests with chiral hosts (usually organic compounds). Herein, we propose inorganic-based CPL-active systems constructed by the “chiral host-luminescent guest” strategy, in which silica acts as a chiral host to endow various luminescent guests with CPL. The chiral silica was modified by silane coupling with amino or phenyl groups to allow interaction with luminescent guests, and then used in combination with acidic achiral dyes, lead-halide type perovskites, and aggregation-induced emission luminogens (AIEgens). Interestingly, when these achiral guests were noncovalently confined in surface-modified chiral silica, the guests showed chiroptical behavior in the circular dichroism (CD) spectra, and thus became CPL active, even though they are not inherently chiral. The surface functional groups on the silica play very important roles in transferring the chiral information from the silica to the guests. This work provides a new concept for constructing CPL-active systems using inorganic materials as a chiral source.
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.
Water driven photoluminescence enhancement and recovery of CH3NH3PbBr3/Silicon oil/PDMS-urea composite
Huang, Sihui,Jiang, Chunli,Lin, Hechun,Liu, Mengqin,Luo, Chunhua,Peng, Hui,Qi, Ruijuan,Travas-Sejdic, Jadranka,Zhang, Ting
, (2020)
Lead halide perovskites (LHPs) are very promising for new optoelectronic devices due to their excellent optical and electronic properties. However, the poor stability against water, heat and UV light greatly restricts their practical applications. In this work, a CH3NH3PbBr3/silicon oil/PDMS-urea composite is prepared by encapsulating CH3NH3PbBr3 nanocrystals and silicon oil into the PDMS-urea polymer matrix. This composite shows characteristics of water-enhanced photoluminescence (PL) and water-driven PL recovery. After immersed in water, the photoluminescence quantum yield of the composite increases from initial 26.0%–52.2%, which is ascribed to the passivation of surface defects by the capping of polymer chains, H3O+ and OH?. The composite possesses superior stability against UV light illumination in water. Furthermore, the composite film exhibits a capability of water-driven PL recovery after UV light irradiation. By applying alternate water/UV treatments, the PL can be reversibly switched “on and off”. The “on/off” ratio value of the PL intensity reached more than 4. These advantages make this composite highly promising in applications utilising luminescent switching and for under water lighting.
