JOURNAL OF LUMINESCENCE
·
2017
·
IF 2.686
Daocheng Hong,Sushu Wan,Yuxi Tian
Organometal halide perovskites have attracted broad interest over the last several years for their promising applications in solar cells and light-emitting devices. It is believed that crystal defects play important roles in the photophysical processes. However, the detailed mechanism is still unclear. In this work, by using luminescence microscopy, we characterized the quenching defects correlating with crystal size, location and morphology. It is clear that needle-shaped crystals own better crystal quality with less defects; and more defects are located in the center of the crystals comparing to the edge. Relatively higher concentration of PbI 2 precursor will generate more defects during the preparation. Characterization of defects is the first step to understand the quenching mechanism and to fully understand the photophysical properties of organometal halide perovskite.
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DOI
高影响因子
Advanced Science
·
2017
·Vol. 5
·期 2
·1700131
·
IF 9.034
Wangen Zhao,Zhun Yao,Fengyang Yu,Dong Yang,Shengzhong (Frank) Liu
Organic–inorganic hybrid halide perovskites are proven to be a promising semiconductor material as the absorber layer of solar cells. However, the perovskite films always suffer from nonuniform coverage or high trap state density due to the polycrystalline characteristics, which degrade the photoelectric properties of thin films. Herein, the alkali metal ions which are stable against oxidation and reduction are used in the perovskite precursor solution to induce the process of crystallization and nucleation, then affect the properties of the perovskite film. It is found that the addition of the alkali metal ions clearly improves the quality of perovskite film: enlarges the grain sizes, reduces the defect state density, passivates the grain boundaries, increases the built-in potential ( V bi ), resulting to the enhancement in the power conversion efficiency of perovskite thin film solar cell.
研究领域:
材料科学
·
光伏技术
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产品关联
DOI
PubMed
高影响因子
PHYSICA B-CONDENSED MATTER
·
2018
·
IF 1.453
J. Su,W.F. Wang,Y. Lei,L. Zhang,L.H. Xu,D. Wang,D. Lu,Y. Bai
In this paper, CH 3 NH 3 PbI 3-x Cl x crystal was grown by solution cooling method with CH 3 NH 3 I and PbCl 2 as raw materials. Lead compounds and CH 3 NH 3 PbI 3-x Cl x crystal with size about 6 mm × 4 mm × 2 mm were obtained. The chemical reactions with different CH 3 NH 3 I/PbCl 2 ratios were analyzed. XPS shows the content of chlorine in CH 3 NH 3 PbI 3-x Cl x is about 0.91%. PXRD, FT-IR, Raman and absorbance spectra were used to study the structure and optical properties of CH 3 NH 3 PbI 3-x Cl x by comparing with CH 3 NH 3 PbI 3 crystal. The CH 3 NH 3 PbI 3-x Cl x crystal grown is of tetragonal structure with the lattice constants a = b = 8.8165 Å, c = 12.7920 Å and the bandgap value of 1.57 eV.
研究领域:
材料科学
·
光伏技术
·
晶体生长
·
半导体材料
✓ 已验证
DOI
高影响因子
Nanoscale
·
2018
·Vol. 10
·期 22
·10538-10544
·
IF 7.233
Jie Ding,Huajing Fang,Zhipeng Lian,Qianrui Lv,Jia-Lin Sun,Qingfeng Yan
A stretchable photodetector was fabricated by releasing a prestrained 3 M very high bond (VHB) substrate coated with perovskite CH3NH3PbI3 microwires and graphene. The light harvesting CH3NH3PbI3 microwires were realized through a transformation from CH3NH3PbI3 bulk single crystals. Graphene served as an expressway for photoinduced carriers in the perovskite. Under a very low working voltage bias of 0.01 V and irradiance power of 13.5 mW cm−2 under 785 nm laser illumination, the responsivity could be as high as 2.2 mA W−1. When the device was stretched up to 30%, 50%, and 80% strain, the responsivity was maintained at 0.96, 0.60, and 0.21 mA W−1, respectively. It also showed a fast photoresponse (<0.12 s) after stretching to 10%, 30%, 50%, 80%, and even to 100%. The device performed well after 100 cycles of stretching to 50% strain.
研究领域:
材料科学
·
光电子学
·
纳米技术
·
柔性电子学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Libo Fan,Songzi Liu,Yan Lei,Ruijuan Qi,Lijia Guo,Xiaogang Yang,Qingbo Meng,Qilin Dai,Zhi Zheng
The utilization of quantum dots (QDs) to improve the performance of perovskite solar cells is attracting much attention due to their unique optical and electronic properties. Most of QDs have to be prepared in advance and then incorporated into the perovskite hosts, which could not ensure the maintenance of their QD characteristics. In this work, we intelligently developed an in situ preparation strategy to disperse AgI QDs homogeneously in the perovskite host for the MAPbI3:AgI(QDs) cross-blended layer directly on indium tin oxide (ITO) via a common and convenient spin-coating process. We combine transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman techniques to demonstrate the cross-blended MAPbI3:AgI(QDs) structure in the final perovskite devices. Furthermore, a series of simply inverted ITO/MAPbI3:AgI(QDs)/PCBM/Ag devices have been designed and fabricated. The photovoltaic performance of these solar cells shows significantly improved short-circuit current density (Jsc) and a champion power conversion efficiency of 16.41% even without a hole transport layer. The current technique induced the crystal growth toward high-quality perovskite films with a homogeneous structure, good crystallinity, less grain boundaries and defects, increased optical path length, and uniform thickness for better solar cell performance. Besides, the impact of the current strategy also lies in an accommodation effect of the hole collection at the ITO side induced by AgI QDs, which modifies the Fermi level of perovskite films, leading to significantly decreased level difference in the Fermi level/work function between the perovskite layer and ITO substrates by ultraviolet photoelectron spectra analysis. More importantly, the charge carrier dynamics of such novel MAPbI3:AgI(QDs) structures were also scrutinized by transient photovoltage analysis.
研究领域:
材料科学
·
光伏技术
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Ming Li,Xiaoqin Yuan,Haoran Ruan,Xiandong Wang,Yongping Liu,Zhenhuan Lu,Jiefeng Hai
A new method for synthesizing freestanding PbS-CH 3 NH 3 PbI 3 (MAPI) core-shell nanoparticles (NPs) with enhanced light absorption and photoelectric properties was reported. The transmission electron microscopy (TEM) and energy dispersive spectrometer (EDS) analysis confirmed the core-shell structure of the obtained sample. The Vis-NIR spectra proved the core-shell sample absorbed light both in visible and near infrared region . For comparison, oleic acid/oleylamine molecule capping PbS NPs, MAPI molecule capping PbS NPs, and PbS-MAPI core-shell NPs were used to fabricate Schottky solar cells. PbS-MAPI core-shell NPs based solar cells delivered a photocurrent response from both the PbS and MAPI, and achieved the highest overall PCE.
研究领域:
材料科学
·
纳米科技
·
光电子学
·
能源材料
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半导体物理
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DOI
高影响因子
Advanced Optical Materials
·
2020
·Vol. 8
·期 15
·2000215
·
IF 8.286
Chandrasekar Perumal Veeramalai,Shengyi Yang,Ruonan Zhi,Muhammad Sulaman,Muhammad Imran Saleem,Yanyan Cui,Yi Tang,Yurong Jiang,Libin Tang,Bingsuo Zou
In general, the fabrication of high-performance, self-powered broadband photodetectors based on traditional semiconducting thin films is tedious and costly. Here, in this paper a high-performance, solution-processed, and self-powered CH 3 NH 3 PbI 3 (MAPbI 3 ) nanocrystal based photodetector ITO/MAPbI 3 /Ag is presented, and it shows broadband photoresponse from the visible to the near-infrared wavelength region. The pronounced enhanced performance of the photodetector is due to taking the advantage of the built-in electric field induced by the work function difference of two electrodes. The optimized photodetector shows a responsivity of 4.9 and 1.42 A W −1 with a specific detectivity of 7.6 × 10 13 and 1.77 × 10 13 Jones under 19 µW cm −2 white light illumination and 26 µW cm −2 808 nm illumination at zero bias, respectively. Therefore, such a concept of simple device geometry and feasible technique will open up a new and promising avenue for the fabrication of self-powered photodetectors and the development of imaging devices.
研究领域:
材料科学
·
光电技术
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 11
·3694-3704
·
IF 7.059
Chen Li,Xin Chen,Ning Li,Jialiang Liu,Beilei Yuan,Yujiao Li,Mei Wang,Fan Xu,Yangqing Wu,Bingqiang Cao
Highly conductive n-type bismuth-doped CH3NH3PbI3 (MAPbI3:Bi) single crystals are successfully grown by the inverse temperature crystallization (ITC) method using bismuth iodide as the dopant source. As revealed by XRD analysis, the Bi-doped MAPbI3 single crystals maintain a perfect cubic perovskite structure (Pmm). Bi3+ ions are successfully incorporated into the MAPbI3 crystal lattice, which induces three orders of magnitude enhancement in the n-type electrical conductivity in a controllable way. Clear Urbach tails in the optical absorption spectra and continuous blue shifts in the room-temperature photoluminescence (PL) spectra are both observed after bismuth doping, which indicates the formation of bismuth induced donors and the release of more electrons to the conduction band. Temperature-dependent PL (TDPL) studies are adopted to study the optical fingerprints of bismuth induced donor defects in the MAPbI3 crystals. By analyzing the TDPL spectra in detail, it is found that the bound exciton (D0X) peak in doped MAPbI3:Bi has a stronger relative intensity and also a significant redshift in comparison with the pristine MAPbI3 crystal. This indicates that stable donor levels are formed in MAPbI3:Bi single crystals by bismuth doping. These results suggest that n-type perovskite crystals have been realized in a controlled doping way, and potential applications in bipolar perovskite-based optoelectronic devices could be realized.
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 52
·期 1
·276-284
·
IF 2.302
Ding Jianxu,Du Songjie,Zhao Ying,Zhang Xiaojun,Zuo Zhiyuan,Cui Hongzhi,Zhan Xiaoyuan,Gu Yijie,Sun Haiqing
Single crystals of organolead trihalide perovskites (CH 3 NH 3 PbI 3 ) are supposed to be one of the most promising materials as photo-detectors. Because of their large absorption coefficient, long-range balanced electron, and hole-transport lengths, it is considered to break through the responsivity and efficiency. To systematically investigate the potentiality as photo-detector, high-quality CH 3 NH 3 PbI 3 single crystals with large size are highly demanded. In the paper, large CH 3 NH 3 PbI 3 single crystals with various crystal shapes were grown from γ-butyrolactone. At optimized precursor concentration and growth temperature, the growth rate was fixed at about 0.2 mm h −1 . Under such growth conditions, the growth steps, originated from screw dislocation on (100) facet, were revealed to be about 0.45 nm. This value is corresponded to half of the unit cell, implying the slow growth rate of (100) facet. With slow growth rate, the absorption edge of the CH 3 NH 3 PbI 3 single crystal was extended to 860 nm, correlated with a calculated bandgap of ~1.44 eV. By depositing a pair of Au electrodes, a metal–semiconductor–metal (MSM) photo-detector on the basis of the CH 3 NH 3 PbI 3 single crystal active layer (3 mm) was fabricated and its photo-response features were investigated systematically. About 2.531 A W −1 responsivity was obtained from the device under 780 nm laser illumination, while the external quantum efficiency reached to 396.20 %, better than some GaN, GaAs, and GaP photo-detectors with a MSM device structure.
研究领域:
材料科学
·
光电技术
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 7
·5331-5342
·
IF 2.993
Segovia Rubén,Ding Leyan,Jiang Hu,Miao Peng,Sun Xiudong,Shi Hongyan,Gao Bo
CH 3 NH 3 PbI 3 (MAPbI 3 ) exhibits distinctive properties for applications in photovoltaics, light emitting devices, photodetectors, and fuel cells. The working temperature of an optoelectronic device affects the photophysical properties of the active material, which is closely related to the device performance. In MAPbI 3 , these properties are intimately connected with its crystalline structure which is temperature dependent. Here, we study the photoluminescence (PL) behavior of MAPbI 3 microwires (MWs) under recursive tetragonal-to-cubic and cubic-to-tetragonal phase transitions induced by temperature cycles from 40 °C (tetragonal phase) to 80 °C (cubic phase). MWs emission exhibited an initial redshift in wavelength by increasing the temperature from the tetragonal to the cubic phase, but after several thermal cycles, this trend reversed and the emission blueshifted. In both phases independently, the emission blueshifted and became stronger with increasing the cycles. The results indicate a thermal cycling-dependent PL and a gradual crystalline structure deformation due to a reiterated change in the MWs lattice, which implies variation in the electronic bandgap along the heating–cooling process. The alteration of the electronic band structure was corroborated by thermal cycling-reflectance measurements. The awareness behavior of material properties upon phase transitions and temperature fluctuations is of great importance for the optimization of optoelectronic devices.
研究领域:
材料科学
·
光学
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DOI
高影响因子
OPTICAL MATERIALS
·
2019
·
IF 2.687
Jiali He,Jinxia Wu,Shuaishuai Hu,Huanglin Shen,Xin Hu
Hybrid structure optoelectronic devices can bring hope to the design of new-generation functional nanodevices because they can combine hybrid structure nanomaterials with flexible and transparent substrates to maximize device miniaturization and usability. Here, we prepared a highly efficient flexible photodetector based on a SnO 2 /CH 3 NH 3 PbI 3 hybrid structure. The photodetector exhibits a very wide spectral response range and fast response speeds. The response speeds is shorter than 0.4 s under 388 nm laser irradiations at 3 V. Moreover, the device demonstrates surprising flexibility under different bending degrees and excellent mechanical stability after many extreme bending cycles. Hence, the great potential properties of inorganic/perovskite hybrid materials will make it into a promising building block in flexible optoelectronics .
研究领域:
光电子学
·
纳米材料
·
柔性电子学
·
光子学
·
材料科学
✓ 已验证
DOI
高影响因子
FERROELECTRICS
·
2019
·
IF 0.697
Weiwei Li,Jiangtao Zeng,Liaoying Zheng,Huarong Zeng,Chunbo Li,Abdelhadi Kassiba,Chulhong Park,Guorong Li
CH3NH3PbI3 (MAPbI3) has attracted great interest of researchers for its impressively high efficiency in solar cells. Researchers have debated whether or not MAPbI3 is ferroelectric for a long time. In this work, the ferroelectric hysteresis loops, dielectric properties, the real part of impedance and domain structure of the samples synthesized in ambient air (not in a glove box) are investigated. No domain switching current is found in the pellets and films at room temperature, but ferroelectric domains are observed in the films with in plane and out of plane conurations. The dielectric constant as a function of temperature shows that there is no ferroelectric to paraelectric phase transition. The complexity and uncertainty concerning the ferroelectricity of the samples synthesized in ambient air are the same as those synthesized in a glove box.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）