Journal of Materials Chemistry A
·
2018
·Vol. 7
·期 3
·1124-1137
·
IF 9.931
Liangxin Zhu,Chong Chen,Fumin Li,Zhitao Shen,Yujuan Weng,Qingsong Huang,Mingtai Wang
To improve the charge separation and transport efficiency in perovskite solar cells (PSCs) with a TiO2-based hybrid mesoscopic/planar architecture, CdS and Cd(SCN2H4)2Cl2 are incorporated into the CH3NH3PbI3 active layer through in situ synthesis to prepare CdS:Cd(SCN2H4)2Cl2:CH3NH3PbI3 bulk-heterojunction films for PSCs. The incorporated CdS and Cd(SCN2H4)2Cl2 improve the quality of perovskite films. Moreover, Cd(SCN2H4)2Cl2 can effectively reduce the defect state density on the CH3NH3PbI3 crystal surface, which decreases charge recombination and facilitates charge transport in PSCs. Furthermore, first-principles calculations show that the I atom of CH3NH3PbI3 has a strong interaction with the Cd atom of CdS, which induces interfacial charge redistribution and charge transfer at the CH3NH3PbI3/CdS interface and therefore decreases the energy of the CH3NH3PbI3:CdS composite system, leading to more efficient electron–hole separation and improved structural stability of the perovskite bulk-heterojunction film. For the above reasons, the CdS:Cd(SCN2H4)2Cl2:CH3NH3PbI3 bulk-heterojunction cell shows much higher efficiency and better stability than the PSCs with pure CH3NH3PbI3. The highest efficiency reaches 20.1%, which is 1.16 times that (17.3%) of the PSCs with pure CH3NH3PbI3 and is also much higher than those of previously reported CH3NH3PbI3 PSCs with a compact/mesoporous TiO2 film. Our research results may provide a new understanding for improving the structural stability and performance of PSCs.
研究领域:
材料科学
·
物理化学
·
太阳能技术
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHEMISTRY COMMUNICATIONS
·
2018
·
IF 4.66
Bo Zhang,Lixia Yang,Jia Wang,Wen Luo,Yaqin Wu,Zhenling Wang
To uncover the distinction in the electronic density of states (DOS) near Fermi level at the graphene and metal, we compare the standard rate constant k 0 values for quinone species at graphene and gold nanoelectrodes, which might be affected by the electronic DOS near Fermi level. The experimental result indicates that the k 0 value obtained at the individual graphene flake of nanometer size is very close to that obtained on gold nanoelectrode, and higher than that at large graphene flake. Unlike the high electronic DOS in gold nanoelectrodes, the difference of k 0 values at graphene nanoelectrodes of different sizes will reveal the size-dependent DOS at single graphene flake.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2023
·
IF 3.9
Qiaocan Huang,Zunxian Yang,Yuanqing Zhou,Yuliang Ye,Bingqing Ye,Zihong Shen,Wenbo Wu,Zongyi Meng,Zhiwei Zeng,Hongyi Hong,Songwei Ye,Zhiming Cheng,Qianting Lan,Jiaxiang Wang,Ye Chen,Hui Zhang,Tailiang Guo,Fushan Li,Yongyi Chen,Zhenzhen Weng
Quantum dots (QDs) with an alloy shell (CdSe@ZnS/ZnS) are one of the most promising emitters for optoelectronic devices for their superior properties such as narrow full width at half maximum (FWHM), high color purity and tunable wavelength. However, the presence of lattice stresses during the internal growth of quantum dots can cause severe exciton bursts. Optimizing the ramp-up process during the core growth of quantum dots and rising the temperature when cladding with ZnS shells is an effective strategy for obtaining high-quality quantum dots. Besides, the stability of quantum dots is further modified by using 1-Octanethiol (OT) as ligands. Detailed analyses of the morphology, colloidal stability, and luminescence performance of QDs were represented. Finally, green CdSe@ZnS/ZnS QLEDs with prolonged carrier lifetimes and less defect state densities achieved peak luminescence at 361850 cd/m 2 with a current efficiency (CE) of 33 cd/A. This work provides a better understanding of the relationship between defect state density and the performance of quantum dots for designing and fabricating high-performance light-emitting diodes.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 35
·18811-18819
·
IF 11.9
Qiang Zhang,Jiadang Li,Nagendra S. Chauhan,Lifei Wang,Zhicheng Huang,Wenhao Fan,Kei Hayashi,Shaoping Chen,Jianfeng Fan,Yuzuru Miyazaki
Grain boundary (GB) scattering has been widely reckoned as a primary restraint on room-temperature (RT) carrier mobility in Mg3Sb2-based materials. In this work, two-dimensional graphene (G) with varied contents was added to single phase Mg3.24Sb1.5Bi0.49Te0.01 materials in order to tailor the highly resistive space-charge region at GBs. The results indicate that introducing G effectively lowers the carrier transport energy barrier Eb from 42 meV (pristine sample) to 18 meV (Mg3.24Sb1.5Bi0.49Te0.01/1.0 vol% G sample), and correspondingly increases the drift mobility by 112.5% from 32 cm2 V−1 s−1 to 68 cm2 V−1 s−1 at RT, leading to an enhanced power factor and thus ZT value. Besides, first-principles calculations were also performed to qualitatively bridge the underlying negative correlation between the electronic density of states (DOS) and GB potential barrier Eb. Moreover, the equivalent nano-particle phonon scattering is also realized through introducing the two-dimensional G, contributing to a moderate reduction in lattice thermal conductivity as quantitatively illustrated based on the Debye–Callaway model. Consequently, the figure of merit ZT for G-added samples is greatly improved in the entire temperature range compared with that of the G-free sample. This study opens up a new avenue for rationally engineering the grain boundary, via regulating interfacial electronic DOS, to optimize electrical transport properties and ZT values.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Yuxiao Fang,Chun Zhao,Ivona Z. Mitrovic,Cezhou Zhao
Radiation hardness is important for electronics operating in harsh radiation environments such as outer space and nuclear energy industries. In this work, radiation-hardened solution-processed ZrLaO thin films are demonstrated. The radiation effects on solution-processed ZrLaO thin films and InOx/ZrLaO thin-film transistors (TFTs) were systemically investigated. The Zr0.9La0.1Oy thin films demonstrated excellent radiation hardness with negligible roughness, composition, electrical property, and bias-stress stability degradation after radiation exposure. The metal-oxide-semiconductor capacitors (MOSCAPs) based on Zr0.9La0.1Oy gate dielectrics exhibited an ultralow flat band-voltage (VFB) sensitivity of 0.11 mV/krad and 0.19 mV/krad under low dose and high dose gamma irradiation conditions, respectively. The low dose condition had a 103 krad (SiO2) total dose and a 0.12 rad/s low dose rate, whereas the high dose condition had a 580 krad total dose and a 278 rad/s high dose rate. Furthermore, InOx/Zr0.9La0.1Oy thin-film transistors (TFTs) exhibited a large Ion/Ioff of 2 × 106, a small subthreshold swing (SS) of 0.11 V/dec, a small interface trap density (Dit) of 1 × 1012 cm–2, and a 0.16 V threshold shift (ΔVTH) under 3600 s positive bias-stress (PBS). InOx/Zr0.9La0.1Oy TFT-based resistor-loaded inverters demonstrated complete swing behavior, a static output gain of 13.3 under 4 V VDD, and an ∼9% radiation-induced degradation. Through separate investigation of the radiation-induced degradation on the semiconductor layer and dielectric layer of TFTs, it was found that radiation exposure mainly generated oxygen vacancies (Vo) and increased electron concentration among gate oxide. Nevertheless, the radiation-induced TFT instability was mainly related to the semiconductor layer degradation, which could be possibly suppressed by back-channel passivation. The demonstrated results indicate that solution-processed ZrLaO is a high-potential candidate for large-area electronics and circuits applied in harsh radiation environments. In addition, the detailed investigation of radiation-induced degradation on solution-processed high-k dielectrics in this work provided clear inspiration for developing novel flexible rad-hard dielectrics.
研究领域:
材料科学
·
电子工程
·
辐射物理
✓ 已验证
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Yuzhu Li,Zongbao Zhang,Yang Zhou,Lai Xie,Naitao Gao,Xubing Lu,Xingsen Gao,Jinwei Gao,Lingling Shui,Sujuan Wu,Junming Liu
Metal halide perovskite solar cells have drawn a lot of attention due to their excellent photovoltaic properties. However, a simple method to prepare perovskite films with high quality in ambient air remains a big challenge, which has become an obstacle for the commercialization of PSCs. Here we propose a facile method to prepare efficient CH 3 NH 3 PbI 3-x (SCN) x -based planar PSCs in ambient conditions and ammonium salts (NH 4 Cl, NH 4 SCN) are used to regulate the microstructure of CH 3 NH 3 PbI 3-x (SCN) x perovskite film prepared in ambient air. At the optimal concentration, the devices with NH 4 Cl or NH 4 SCN additives achieve the champion efficiency of 14.71% and 16.61% respectively, which are much higher than the 12.97% of the reference device. The stability of the unsealed devices with additives in ambient air has also been significantly improved. The modified devices without any encapsulation still retain about 80% of initial efficiency after 30 days in ambient air. The conductive atomic force microscopy and photoluminescence measurement are used to characterize photoelectric properties of perovskite film. The trap-state density and charge recombination of the devices have been investigated. The results suggest that the improved photovoltaic characteristics and stability may be attributed to the improved quality of perovskite films, the reduced trap states and the suppressed charge recombination.
研究领域:
材料科学
·
能源技术
·
光伏器件
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 10
·3470-3476
·
IF 7.393
Yiwei Zhang,Fengjing Liu,Chao Jiang,Fawei Tang,Xinping Zhang
The robust material tunability of the hybrid organic–inorganic perovskite (HOIP) has attracted considerable research interests to explore the application in photoelectronic devices. Huge hysteresis has been recognised as a main problem in HOIP-based photoelectric devices; the origin of hysteresis has been attributed to the ion migration and trap states in HOIP materials. In this study, we designed and synthesised a HOIP single crystal with one-dimensional structure where the PbI42− octahedron is caged by the organic chains. The ion migration can be dramatically suppressed by the quantum size effect. Besides, in the single crystal trap states density is ultra-low due to the absence of grain boundaries. As a result, photodetectors based on this 1D HOIP single crystal show negligible hysteresis I–V curves. Moreover, a high quality ohmic contact is formed between electrodes and 1D HOIP, which is beneficial for photocarrier extraction. A responsivity of 80 mA W−1 and EQE of 30% are realised. The response speed is determined to be less than 0.4 ms. In addition, the photodetectors based on the novel 1D single crystal present good stability; after 3 months of ambient storage, 85% of its original photocurrent generation ability is retained.
研究领域:
材料科学
·
光电技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2015
·
IF 6.723
Yingpan Song,Huifang Hu,Miao Feng,Hongbing Zhan
The density of electronic states (DOS) is an intrinsic electronic property that works conclusively in the electrochemistry of carbon materials. However, seldom has it been reported how the DOS at the Fermi level influences the electrochemical activity. In this work, we synthesized partially and fully unzipped carbon nanotubes by longitudinally unzipping pristine carbon nanotubes (CNTs). We then studied the electrochemical activity and biosensitivity of carbon materials by means of the CNTs and their derivatives to elucidate the effect of the DOS on their electrochemical performances. Tailoring of the DOS for the CNT derivatives could be conveniently realized by varying the sp2/sp3 ratio (i.e., graphite concentration) through manipulating the oxidative unzipping degree. Despite the diverse electron transfer mechanisms and influence factors of the four investigated redox probes (IrCl62–, [Fe(CN)6]3–, Fe3+, and ascorbic acid), the CNT derivatives exhibited consistent kinetic behaviors, wherein CNTs with a high DOS showed superior electrochemical response compared with partially and fully unzipped carbon nanotubes. For biological detection, the CNTs could simultaneously distinguish ascorbic acid, dopamine, and uric acid, while the three CNT derivatives could all differentiate phenethylamine and epinephrine existed in the newborn calf serum. Moreover, the three CNT derivatives all presented wide linear detection ranges with high sensitivities for dopamine, phenethylamine, and epinephrine.
研究领域:
材料科学
·
电化学
·
生物医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2022
·Vol. 33
·期 8
·5564-5574
·
IF 2.779
Li Zhen,Chen Yingying,Lang Haoze,Wan Jianghong,Gao Yan,Dong Haitao,Zhang Xiaoke,Feng Wenran
The ternary Pb–SnSe thin films were prepared using chemical bath deposition (CBD) and sensitized with iodine. The chemical formula of the films was recognized as Pb 0.8 Sn 0.2 Se, according to the stoichiometric ratio. The films are both centered cubic crystal structure and show preferred orientation in PbSe (200). The optical band gap ( E g ) is found to decrease after sensitization, due to the impurity energy levels created by PbI 2 . The photoelectric performance of the Pb 0.8 Sn 0.2 Se thin films is significantly improved after iodine sensitization. Accordingly, the resistance change rate, i.e., the photoelectric sensitivity is enhanced over 35%, which is over 161% for more than 4 on/off cycles. The density of states (DOS) of Pb 0.8 Sn 0.2 Se is calculated using the first-principle method. The calculation shows that the I dangling bond in sensitized Pb 0.8 Sn 0.2 Se introduces a large DOS inside the band gap and causes the narrowing of the band gap.
研究领域:
材料科学
·
半导体物理
·
光电化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Guodong Su,Benlin He,Zekun Gong,Yang Ding,Jialong Duan,Yuanyuan Zhao,Haiyan Chen,Qunwei Tang
Carbon-based all-inorganic CsPbBr 3 perovskite solar cells (PSCs) have attracted growing interests due to low cost and excellent tolerances toward moisture, temperature, oxygen and ultraviolet light. However, carrier recombination of CsPbBr 3 film and large energy level differences at CsPbBr 3 /carbon interface are still the most crucial problem for further enhancement of power conversion efficiency. In the current study, an intermediate energy level at CsPbBr 3 /carbon interface and CsPbBr 3 film passivation are employed by coating hexane solution of CsPbBr x I 3-x nanocrystals (NCs) on the perovskite layer. Through systematic study on interfacial engineering , it is found that CsPbBr x I 3-x NCs with tunable energy level can remarkably reduce energy loss and hexane under passivation treatment can enlarge perovskite grain size as well as reduce trap state density. A champion power conversion efficiency of 9.45% is achieved for CsPbI 3 NCs tailored all-inorganic CsPbBr 3 PSC in comparison with 5.26% for NCs-free device, with the unencapsulated carbon-based CsPbBr 3 PSC exhibiting remarkable long-term stability over 900 h in 80% relative humidity air atmosphere at 25 °C. This work provides an effective approach to promote charge extraction and reduce defect states density as well as enhance the performance of PSCs.
研究领域:
材料科学
·
光伏技术
✓ 已验证
产品关联
DOI
高影响因子
Solar RRL
·
2020
·Vol. 4
·期 10
·2000362
·
IF 7.527
Xueke Li,Benlin He,Zekun Gong,Jingwei Zhu,Wenyu Zhang,Haiyan Chen,Yanyan Duan,Qunwei Tang
Carbon-based CsPbBr 3 perovskite solar cells (PSCs) without hole-transporting layers (HTLs) have aroused extensive attention due to their low manufacturing cost and prominent ambient stability. However, the defects of perovskite film and the poor charge extraction within PSCs result in severe charge recombination, which restricts the further enhancement of device efficiency. In view of this critical point, a compositional engineering of CsPbBr 3 perovskite via doping with Cl − ions is presented herein to decrease the trap states and enhance the charge extraction. It is revealed that the doping of Cl − ions not only enlarges the grain size and thereby reduces the trap-state density, but also optimizes the energy-level alignment and improves the hole mobility of the perovskite film, leading to an evidently suppressed charge recombination and improved charge extraction and transportation. As a result, a champion power conversion efficiency (PCE) of 9.73% is achieved for carbon-based HTL-free CsPbBr 2.98 Cl 0.02 PSC, yielding a marked enhancement in comparison with 6.69% efficiency for the control. Meanwhile, the thermal and moisture stabilities of unencapsulated CsPbBr 2.98 Cl 0.02 PSC are improved, maintaining 93% and 95% of the initial PCE after expose to air atmosphere with 80% relative humidity (RH) and at 80 °C over 60 days, respectively.
研究领域:
材料科学
·
太阳能电池技术
·
光电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2017
·
IF 4.536
Wei-Long Xu,Meng-Si Niu,Xiao-Yu Yang,Peng-Qing Bi,Kang-Ning Zhang,Chao Xiong,Hong-Chun Yuan,Trevor A. Smith,Kenneth P. Ghiggino,Xiao-Tao Hao
Perovskite microplates have important implications in the fields of functional electronics and optoelectronics. We report a facile strategy, antisolvent treatment for the growth of perovskite microplates. The morphology and crystalline quality of the microplates could be controlled by the amount of the chlorobenzene antisolvent used. An appropriate amount of antisolvent facilitates the formation of high-quality perovskite microplates with no residual precursor remaining. Spatially and temporally resolved fluorescence measurements demonstrate the heterogeneity of defect-state density and recombination processes in various perovskite microplate regions. The body center shows higher defect state density when compared with that at the edge or the corner of the microplate. Excessive antisolvent degrades the microplates into smaller particles. The results of this study reveal the factors that influence the crystallization process and photophysical dynamics of perovskite microplates.
研究领域:
材料科学
·
光学
✓ 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）