APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Jungang He,Mohan Yuan,Xia Wang,Xiao Chen,Xiang Peng,Liuyong Hu,Xue Zhao,Jing Liu,Jinghui Li,Kanghua Li,Chao Chen,Jiang Tang
Photodetectors with a broad spectral range play significant roles in optoelectronic applications. Introducing impurity atoms with the desired energy levels in semiconductors is an effective way to extend the spectral response range of photodetectors . Here, we demonstrate an extrinsic photodetector by introducing Ag + cations in methylammonium lead bromide (MAPbBr 3 ). The 5 % Ag-doped MAPbBr 3 single crystals exhibit excellent response with a high responsivity up to 0.56 A/W, a high detectivity of 2.22 × 10 10 jones, and a high response speed of 0.30 s/0.12 s under 700 nm wavelength illumination. Moreover, by the detailed investigation of the crystallinity and energy level distribution, we find that the Pb 2+ in MAPbBr 3 crystals is partially substituted by the Ag + impurities, which form the sensitive centers and thus induce the extrinsic response by the photo-carriers transition from the valence band to the sensitive centers. These results extend the spectral response region of perovskite optoelectronic applications and indicate the role of doping impurities with the desired energy level in improving the extrinsic response.
研究领域:
材料科学
·
光学工程
·
半导体物理
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Electronic Materials
·
2020
·
IF 0
Jun-Hua Wei,Xu-Dong Wang,Jin-Feng Liao,Dai-Bin Kuang
Ligand-assisted reprecipitation strategy (LARS) is one of the most popular methods for the fabrication of lead halide perovskite nanocrystals; however, it has always been criticized for poor repeatability and low stability of the resulting nanocrystals. Herein, we demonstrate that liquefying MAPbBr3 single crystals via methylamine (MA) gas rather than being dissolved in N,N-dimethylformamide (DMF) are more beneficial in synthesizing high-quality and stable MAPbX3 (X = Cl, Br, I) based on the LARS. In particular, the liquefied single-crystal-derived MAPbBr3 nanocrystals show a high PLQY exceeding 95%, while 87% for the one derived from the traditional LARS. It is found that replacing DMF solvent with MA gas can not only passivate the MA vacancy defects on the nanocrystal surface but also hinder the formation of halide vacancies, both of which significantly enhance the stability. Benefitting from the impressive PLQY and high X-ray attenuation, MAPbBr3 nanocrystals exhibit strong radioluminescence under X-ray excitation, which further enables their application in large-area X-ray imaging. Furthermore, liquefied perovskite single crystals can be further applied in the in situ synthesis of MAPbX3 nanocrystals within the mesoporous SiO2 template, affording the MAPbX3@SiO2 complex, which exhibits potential as stable solid-state light-emitting diodes.
研究领域:
材料科学
·
纳米技术
·
光电
·
放射学
✓ 已验证
DOI
Light-Science & Applications
·
2020
·Vol. 9
·期 1
·1-11
·
IF 13.714
Liu Kai-Kai,Liu Qian,Yang Dong-Wen,Liang Ya-Chuan,Sui Lai-Zhi,Wei Jian-Yong,Xue Guo-Wei,Zhao Wen-Bo,Wu Xue-Ying,Dong Lin,Shan Chong-Xin
Poor stability has long been one of the key issues that hinder the practical applications of lead-based halide perovskites. In this paper, the photoluminescence (PL) quantum yield (QY) of bromide-based perovskites can be increased from 2.5% to 71.54% by introducing water, and the PL QY of a sample in aqueous solution decreases minimally over 1 year. The enhanced stability and PL QY can be attributed to the water-induced methylamino lead bromide perovskite (MAPbBr 3 )@PbBr(OH). We note that this strategy is universal to MAPbBr 3 , formamidine lead bromide perovskite (FAPbBr 3 ), inorganic lead bromide perovskite (CsPbBr 3 ), etc. Light-emitting devices (LEDs) are fabricated by using the as-prepared perovskite as phosphors on a 365 nm UV chip. The luminance intensity of the LED is 9549 cd/m 2 when the driven current is 200 mA, and blemishes on the surface of glass are clearly observed under the illumination of the LEDs. This work provides a new strategy for highly stable and efficient perovskites.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2021
·
IF 3.599
Ye Zhang,Xue Lou,Xiaochun Chi,Quan Wang,Ning Sui,Zhihui Kang,Qiang Zhou,Hanzhuang Zhang,Li Li,Yinghui Wang
The temperature-dependent time-resolved spectroscopies are employed to investigate the hot carrier characteristics in MAPbBr 3 nanocrystals (NCs). Simultaneously, the absorption and photoluminescence data exhibits that MAPbBr 3 NCs pass through cubic phase and tetragonal phase in turn as the temperature drops. As the phase transition from the cubic phase to the tetragonal phase, the band gap narrows, the shallow defects population that participates in the carrier dynamics and the Longitudinal-optical phonon energy ( E LO ) decreases. We uncovered that the hot carrier can be induced in the MAPbBr 3 NCs through changing the photon flux and the temperature. Moreover, the hot carrier cooling time and the carrier heating effect in tetragonal phase improved in comparison with those in cubic phase, owing to the influence of bandgap, shallow defect and E LO as mentioned above. These results can help us to further understand the hot carrier characteristics in the perovskite MAPbBr 3 NCs for designing and optimizing the perovskite-based optoelectronic devices of high performance.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Materials Chemistry Frontiers
·
2021
·Vol. 5
·期 24
·8319-8332
·
IF 6.482
Zhanwei Zhou,Jiuyuan Xu,Yuxuan Liu,Chen Wei,Hengyang Zhang,Qun Wang
The B-site doping of organic–inorganic lead halide perovskites of the form MAPbX3 is not only an effective way to improve energy conversion (solar-electrical, thermal-electrical, solar-chemical, etc.) performance, but it is also eco-friendly, reducing the toxic Pb content. To the best of our knowledge, there are few reports on the photocatalytic and thermoelectric properties after the partial doping of Zn2+ into the Pb2+ lattice sites of perovskite MAPbBr3 crystals fabricated through a solvothermal route (Zn–MAPbBr3). Systematic characterization, including XRD, EDS, XPS, UV-vis, PL, N2 adsorption/desorption, Hall measurement, time-resolved photoluminescence measurement (TRPL), and electrochemical analysis, showed that the smaller Zn2+ guests increase the Goldschmidt tolerance and octahedral tilting factor of MAPbBr3 and enhance the carrier concentration, carrier mobility and conductivity, active site number, and oxidation abilities of Zn–MAPbBr3. Finally, Zn–MAPbBr3 crystals exhibited an improved absorption capacity and better photocatalytic degradation performance toward RhB dye and improved thermoelectric transportation properties, including better electrical conductivity and a more positive Seebeck coefficient, compared with pristine MAPbBr3.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 54
·期 17
·11596-11603
·
IF 3.442
Shen Hongxia,Nan Ruihua,Jian Zengyun,Li Xiaojuan
Perovskite MAPbBr 3 (MA = CH 3 NH 3 + ) single crystals were grown via the anti-solvent vapor-assisted crystallization method. The crystal growth process was optimized by adjusting the solution concentration and diluting the anti-solvent. The maximum size of the obtained crystal was 9 × 9 × 3 mm 3 . It shows that the MAPbBr 3 single crystal is a cubic structure, the space group is Pm \( \bar{3} \) m , and the lattice constant is 0.59062 nm. Furthermore, its energy band gap is approximately 2.23 eV. The atomic force microscopy results demonstrated that the growth process of MAPbBr 3 single crystal followed the defect step growth mechanism, which was controlled by the screw dislocations within the crystal. Based on the curling growth of a screw dislocation on the crystal surface, a spiral step was formed. After the step was rotated around the entire mesa, a higher step was generated. Repeatedly, the step growth of screw dislocation within the crystal came into being. Besides, some small pits were also observed on (100) plane of the MAPbBr 3 crystal. These pits hindered the movement of steps and affected the lattice arrangement around them, causing the structural mismatch and more defects within the crystals.
研究领域:
材料科学
·
晶体学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2021
·
IF 3.512
Gaocai Li,Chen Zhao,Yang Liu,Jiwei Ren,Ziming Zhang,Haipeng Di,Wei Jiang,Jun Mei,Yiying Zhao
Long-life and self-powered betavoltaic batteries are extremely attractive for many fields that require a long-term power supply, such as space exploration, polar exploration, and implantable medical technology. Organic lead halide perovskites are great potential candidate materials for betavoltaic batteries due to the large attenuation coefficient and the long carrier diffusion length, which guarantee the scale match between the penetration depth of β particles and the carrier diffusion length. However, the performance of perovskite betavoltaics is limited by the fabrication process of the thick and high-crystallinity perovskite film. In this work, we demonstrated high-performance perovskite betavoltaic cells using thick, high-quality, and wide-band-gap MAPbBr3 polycrystalline films. The solvent annealing method was adopted to improve the crystallinity and eliminate the pinholes in the MAPbBr3 film. The optimal MAPbBr3 betavoltaic cell achieved a power conversion efficiency (PCE) of 5.35% and a maximum output power of 1.203 μW under radiation of electrons of 15 keV with an equivalent activity of 253 mCi. These results are a nearly 50% improvement from previous reports. Effects of the MAPbBr3 perovskite layer thickness on the device performance were also discussed. The mechanisms of film-growth processes and device physics could provide insights for the research community of perovskites and betavoltaics.
研究领域:
材料科学
·
能源技术
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2024
·
IF 2.9
Yanzhuo Hu,Dong Liu,Ying-Bo Lu,Hao Wang,Zhongchen Wu,Hexin Bao,Ruijie Zou,Xianyuan Jiang,Wei-Yan Cong,Chengbo Guan
The excitonic effect significantly influences the optoelectronic characteristics of halide perovskites. However, consensus on the temperature modulated exciton binding energy remains elusive, even for extensively studied materials like MAPbBr3 perovskites. In this study, we utilized UV-vis absorption spectra and the Elliott model to extract the exciton binding energies of MAPbBr3 in the range of 170–290 K. Elliott model fitted results reveal a linear increasing trend in bandgap and exciton binding energy for both cubic and tetragonal phases with temperature, with the tetragonal phase exhibiting a higher increasing rate. Additionally, we found that regardless of the temperature, the strongest absorption peaks are always dominated by the exciton absorption, and our fitted exciton absorption peak blue-shifts with the increase of temperature, accounting for the observed blue-shift of the strongest absorption peak for our fabricated MAPbBr3 sample. However, with the increase of temperature, the weight of continuum state absorption increases significantly, which widens the absorption tails to the longer wavelength, leading to the red-shift of Tauc-plotted optical bandgaps. This is the first work considering the temperature-modulated excitonic properties of halide perovskites, which offers valuable insights into the behavior of MAPbBr3 under varying temperature conditions. After a series of theoretical simulations on the temperature modulated electronic properties, including band structures, carrier effective masses, optical dielectric properties and Born effective charges, we provide rational interpretations for the experimentally observed temperature induced variation of the optical properties. These works are helpful to deepen our understanding of the temperature modulated optical properties of MAPbBr3 perovskites.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Pengbin Gui,Yanming Sun,Liangpan Yang,Zhaosheng Xia,Shuxin Wang,Zhouyin Wang,Zhiliang Chen,Wei Zeng,Xingang Ren,Siliang Wang,Guojia Fang
Metal halide-perovskite-based photodetectors have recently emerged as a class of promising optoelectronic devices in various fields. Meanwhile, nano/microstructuring perovskite-based photodetectors are a facile integration with complementary metal-oxide semiconductors for miniaturized imaging systems. However, there are still challenges to be overcome in reducing the losses caused by light reflection on the surface of microstructural perovskites. In this work, surface microstructure engineering is employed in MAPbBr3 microsheets for reducing light reflection and improving light absorption, resulting in high-performance perovskite photodetectors. MAPbBr3 microsheets, which possess different surface morphologies of flat, upright hemisphere arrays and inverted hemisphere arrays (IHAs), are fabricated by a simple microstructure template-assisted space confinement process. The light absorption capacity of IHA MAPbBr3 is significantly higher than that of the other two structures. Hence, IHA photodetectors with excellent figures of merit, including low dark current, decent responsivity, and fast speed, are achieved. Furthermore, the noise of the IHA photodetectors is only ∼10–13 A/√Hz, which results in the superior sensitivity for weak light detection with a specific detectivity up to 1011 Jones. Our results demonstrate that surface engineering is a simple, low-cost, yet effective approach to improve the performance of nano-/micro-optoelectronic devices.
研究领域:
材料科学
·
光学工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHYSICS-CONDENSED MATTER
·
2022
·Vol. 34
·期 40
·405703
·
IF 2.745
Chao Liu,Hang Chen,Ping Lin,Haihua Hu,Qingyu Meng,Lingbo Xu,Peng Wang,Xiaoping Wu,Can Cui
MAPbBr3 single crystal (SC) thin layer was successfully grown on MAPbCl3 SC substrate to form perovskite SC heterojunction. Planar structure electrodes are deposited by thermal evaporation on the surfaces of MAPbCl3, MAPbBr3, and SCs heterojunction, respectively to evaluate their photoelectric performance. The SC heterojunction device exhibits excellent unidirectional conductivity in the voltage-current curves. Meanwhile, the current–time curves prove that SC heterojunction devices can effectively utilize the advantages of MAPbCl3 and MAPbBr3, possessing relatively low dark current (∼300 nA), which is comparable to the dark current of MAPbCl3, but very high photocurrent (∼3500 nA), which is equivalent to the photocurrent of MAPbBr3. Rather than the photocurrent overshot and decay occurring at the exposure of light illumination in the MAPbBr3 device, the photocurrent is extremely stable without overshot and decay in the SC heterojunction device. The light-to-dark ratio of the SC heterojunction device is twice that of MAPbCl3 device and three times that of MAPbBr3 device. Furthermore, the detectivity of the heterojunction device reaches as high as \sim\!\!{\text{7}} \times {\text{1}}{{\text{0}}^{{\text{11}}}}{\text{ Jones}}, an order of magnitude higher than MAPbCl3 and MAPbBr3. The excellent characteristics of SC heterojunction further expand the practical application prospect of perovskite materials.
研究领域:
材料科学
·
光电子学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2020
·
IF 2.87
Haipeng Di,Wei Jiang,Hao Sun,Chen Zhao,Feiyi Liao,Yiying Zhao
Fabricating perovskite single-crystal thin films (SCTFs) in controllable manner is the major challenge for the promising potential applications in optoelectronic devices. Although modifying the substrate surface is frequently used to realize the controlled growth of perovskite SCTFs, it is still unclear how the substrate condition affects the crystallization process. In this work, we systemically investigated the effects of the surface hydrophobicity of indium tin oxide substrates on the crystallization process of MAPbBr3 SCTFs prepared by the space-confined method. Comprehensive characterizations show that the surface morphology and crystallinity of SCTFs are improved, and the defect density is reduced when increasing the substrate hydrophobicity. The best MAPbBr3 thin film obtained has a full width at half-height of the rocking curve of the (001) crystal plane of 0.044°. The mechanism of the substrate hydrophobicity on the crystal growth is also discussed. These results will provide guidance to the controllable growth of high-quality SCTFs for perovskite SCTF devices.
研究领域:
材料科学
·
光电材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry Letters
·
2019
·
IF 7.329
Zhang-Ran Gao,Xiao-Fan Sun,Yu-Ying Wu,Yi-Zhang Wu,Hong-Ling Cai,X. S. Wu
Hybrid organic–inorganic halide perovskites (HOIPs) MAPbBr3 and their ramifications have emerged because of the photovoltaic, optical, and other fascinating performances of HOIPs in recent years. However, many intrinsic properties, such as crystal structure and ferroelectricity, are still controversial. In this work, the ferroelectricity of the orthorhombic and tetragonal MAPbBr3 single crystal was confirmed through the dielectric behavior versus bias electric field ε(E), the temperature-dependent pyroelectric current with positive/negative poling, and the positive-up-negative-down (PUND) measurements. The electric field dependence of dielectric constant curves shows a butterfly type shape in the orthorhombic and tetragonal phase. The pyroelectric current shows two maxima at 155 and 245 K, corresponding to ferroelectric–ferroelectric and ferroelectric–paraelectric phase transitions, respectively. In particular, the direction of the pyroelectric current can be reversed by a positive or negative poling electric field, which is the assertive evidence of ferroelectricity. The PUND measurements act as the most convincing proof of the ferroelectricity of the MAPbBr3 single crystal. This work reports new evidence of the ferroelectric properties of the MAPbBr3 single crystal, which provides the intrinsic property when considering their high power conversion efficiencies.
研究领域:
材料科学
·
凝聚态物理
·
光伏
·
铁电学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）