ORGANIC ELECTRONICS
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2021
·
IF 3.721
Li Xiang,Xuekai Huang,Ya Wang,Zhilong Xin,Gaoda Chai,Yangbing Xu,Kai Wang,Jun Chen,Chuan Liu,Xinwei Wang,Shengdong Zhang,Hang Zhou
X-ray detection is an important technology for medical diagnosis as well as industrial and security inspections. While today's commercial X-ray detectors are bulky, photodetectors based on organic semiconductors have attracted increasing attention owing to their low temperature processing capabilities, flexibility and low cost. Nonetheless, the low X-ray attenuation coefficient of organic semiconductors still hinders their practical application. Herein, a new organic-inorganic hybrid strategy is proposed to improve the X-ray sensitivity of organic photodetectors (OPDs). A solution-processed X-ray sensitive hybrid OPD is fabricated by embedding CsPbBr 3 quantum dots (QDs) into a P3HT:PC 61 BM bulk heterojunction photodiode . The QDs, acting as embedded scintillators in the organic active layer, maintain a high radioluminescence . The proposed hybrid structure enables indirect X-ray detection in a comprehensive manner. These hybrid photodetectors exhibit suppressed dark current densities in the range of tens of picoamperes per square centimeters for different weight ratios of blended QDs. The best OPD achieves a sensitivity of 229.6 e nGy −1 mm −2 (3.67 μC Gy −1 cm −2 ) and a dark current of 23.3 pA cm −2 at a low operating voltage (−3 V) for 20–80 kV “soft” X-rays, thus representing great potential for the development of next generation low cost, portable, and highly sensitive X-ray detectors.
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Laser & Photonics Reviews
·
2021
·Vol. 15
·期 10
·2100169
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IF 13.138
Yalun Xu,Wei Li,Tian Yu,Yanyan Li,Ruiming Li,Qianqian Lin
Conventionally, the detection of pulsed-lasers is mainly based on thermal effects, such as thermoelectric detectors and pyroelectric detectors, which possess a photothermal conversion process, resulting in slow response and significant energy loss. Fast photodiodes are also introduced to calibrate pulsed-lasers. However, they require advanced oscilloscopes with high bandwidth and amplification systems, limiting their practical application to some extent. To address the issues of these two types of pulsed-laser detectors, an interfacial modification strategy is introduced to the conventional perovskite photodiodes. The incorporation of the polyvinylidene fluoride layer can effectively slow down the photovoltage decay of the perovskite devices via electric-field induced polarization, which enables the detection of both modulated light emitting diodes and ultra-fast pulsed-lasers in a facile way. With such effect, the polyvinylidene fluoride (PVDF) based photodetectors can effectively convert the pulsed light input to a quasi-DC output, which can be easily recorded with a multimeter or source meter. These devices also exhibit low noise voltage of <10 −5 V Hz −1/2 , high responsivity of >2 × 10 4 V W −1 @ 1 µW cm −2 , indicating great potential for real applications.
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ADVANCED FUNCTIONAL MATERIALS
·
2021
·Vol. 31
·期 36
·2103949
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IF 18.808
Liangbin Xiong,Jiashuai Li,Feihong Ye,Haibing Wang,Yaxiong Guo,Xing Ming,Qingyun Chen,Shaoan Zhang,Ruihao Xie,Zhanxu Chen,Yang Lv,Guangqi Hu,Yingji He,Guojia Fang
SnO 2 compact layer (c-SnO 2 ) frequently suffers from degradation in high temperature processes (HTP) such as crack, worse interfacial contact, and electrical properties, that is, annealing effect. To solve this problem, a kind of bifunctional SnO 2 colloid is developed by using small molecular oxalate whose organic components can be removed clearly at a low temperature process (LTP). The c-SnO 2 and SnO 2 mesoporous layer (m-SnO 2 ) derived from the fresh and aged sols with the same colloid show no annealing effect, decreasing oxygen vacancy, and adsorbing water on increasing annealing temperature. The champion devices of LTP and HTP SnO 2 planar perovskite solar cells (PSCs) achieve, respectively, stabilized photoelectric conversion efficiencies (PCEs) of 20.74% and 20.70%. In contrast, the performance of champion devices of their mesoporous counterparts is significantly improved, showing nearly hysteresis free character with stabilized PCEs of 22.40% and 22.37%, respectively. The inclusion of m-SnO 2 plays a role of an energy bridge, improving electrons collection efficiency, which is supported by photoluminescence and transient photoluminescence characterizations. HTP SnO 2 mesoporous PSCs can preserve 97.6% and 80% of their initial PCEs after aging for 25 weeks and 8-h irradiated/16-h dark cycle within 104 h. The high stability of HTP SnO 2 PSCs may ascribe to low oxygen vacancy and adsorbed water of HTP SnO 2 .
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Journal of Physical Chemistry C
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2021
·
IF 4.126
Rui Han,Qian Zhao,Jian Su,Xiaojun Zhou,Xiaofang Ye,Xiaojuan Liang,Juan Li,Hongkun Cai,Jian Ni,Jianjun Zhang
The best research-cell efficiency for quantum dot solar cells has boosted from 11.6 to 18.1% within 5 years due to the evolution of perovskite quantum dots (PQDs) that are being intensively developed along with the flourishing of perovskite thin-film photovoltaics. During the fabrication of PQD devices, as far as we know, methyl acetate (MeOAc) is an ineluctable solvent in ligand exchange for producing highly efficient solar cells. Nevertheless, the reproducibility for PQD solar cells using MeOAc treatment is poor since it has to make a trade-off between removing long-chain organic ligands for high charge transport and keeping them for the stabilization of the black crystal phase. Herein, we demonstrate the degree of MeOAc treatment on CsPbI3 PQD solid films in detail and clarify that MeOAc treatment is able to not only remove the oleyl ligands for promoting the charge transport but also passivate the surface defects in the CsPbI3 PQD solid films. It is noted that immoderate MeOAc treatment could induce the formation of the δ-phase, leading to the degradation of device performance. After locating the balance for MeOAc treatment, the CsPbI3 PQD solar cells are fabricated and optimized without using any additional modifications except MeOAc treatment, and these additive-free devices possess a conversion efficiency surpassing 12%.
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Inorganic Chemistry Frontiers
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2021
·Vol. 8
·期 12
·3077-3084
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IF 6.569
Jiani Zhang,Huaizhong Shi,Yue Song,Wenjing Xu,Xianyu Meng,Jiyang Li
Titanium silicalite-1 (TS-1) zeolite, as a promising shape-selective catalyst, has excellent catalytic activity in many oxidation reactions. However, there are still challenges to rapidly synthesize TS-1 and achieve a high content of Ti in TS-1 without anatase TiO2. In this work, a high-efficiency strategy has been proposed by using 1,3,5-benzenetricarboxylic acid (H3BTC) as a crystallization modifier to rapidly synthesize enhanced-Ti TS-1 zeolite without extra-framework anatase TiO2. In such a synthetic system, a mixed liquid–solid precursor phase is formed within 4.5 hours, and then TS-1 crystals can be produced within one day based on the special combination mechanism of liquid-phase and solid-phase conversion. Ti species enter into the TS-1 framework by the transformation from the liquid phase to crystals as well as by the in situ transformation of the solid phase, which makes the content of framework Ti increase significantly, and the Si/Ti ratio can reach 48.5 without any anatase TiO2. In the epoxidation of 1-hexene with H2O2 as an oxidant, the conversion of alkene over the synthesized TS-1 was improved by 8.01% compared to the traditional TS-1 (18.11% vs. 10.10%). The high-efficiency strategy reported in this paper will provide new opportunities for further promoting the industrial application of TS-1 zeolite.
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JOURNAL OF CHROMATOGRAPHY A
·
2021
·
IF 4.759
Yuanyuan Fu,Zhentao Li,Qiaoyan Li,Changjun Hu,Yikun Liu,Wenqi Sun,Zilin Chen
Covalent organic frameworks (COFs), considered as a series of newly emerging porous organic materials, have been widely utilized in separation fields. Herein, a novel COF (TFPB-BD) was first employed as stationary phase for high-efficiency capillary electrochromatographic separation. Benzidine (BD) and 1,3,5-Tris-(4-formylphenyl)benzene (TFPB) were selected as organic linkers and then introduced into the aldehyde group modified capillary for the in situ growth of TFPB-BD onto the capillary inner wall at room temperature. The morphology and formation of TFPB coated capillary column were confirmed by a variety of tools including Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). It's interesting that the TFPB globular crystals with nanoscale were uniformly and densely modified on the capillary inner surface. Hence, the prepared column exhibited prominent separation performance for the test analytes including alkylbenzenes, chlorobenzenes and phenolic compounds with high efficiency and high resolution. The maximum column efficiency can reach about 1.8 × 10 5 plates•m −1 . Additionally, the high resolutions of anilines, amino acids and parabens were also achieved on the TFPB modified capillary. The precisions (RSDs) of the retention times of alkylbenzenes of intra-day runs ( n = 3), inter-day runs ( n = 3) and parallel columns ( n = 3) were all less than 2.83%. This innovative COF-based stationary phase gives great promise for the chromatographic separation field.
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PubMed
高影响因子
ACS Applied Electronic Materials
·
2021
·
IF 3.314
Haodong Tang,Siqi Jia,Shihao Ding,Pai Liu,Jingrui Ma,Xiangtian Xiao,Xiangwei Qu,Haochen Liu,Hongcheng Yang,Bing Xu,Wei Chen,Guangyu Li,Zoe Pikramenou,Carl Anthony,Kai Wang,Xiao Wei Sun
Ink-jet printing is a promising deposition technology, which is capable of large-area fabrication and mask-free patterning. For ink-jet-printed quantum dot (QD) light-emitting diodes (LEDs), the QDs are commonly dissolved in a mixture of solvent and thickener ink system. However, the hole transport layer could be eroded by this QD ink, leading to a rough surface morphology and resulting in the leakage of carriers and low device performance. This phenomenon was first and directly observed by using an atomic force microscope and a cross-sectional scanning electron microscope. We, therefore, redesigned the annealing process of the hole transport layer to achieve an optimized smooth surface with a reduced number of defects for ink-jet-printed QD LEDs (QLEDs). Optimized morphology brings back a maximum luminance of over 30,000 cd/m2 and an external quantum efficiency of 7.52% for the ink-jet-printed red QLEDs using CdSe QDs, which are comparable to those of the spin-coated device. Moreover, the operation lifetime of the ink-jet-printed device is also enhanced by the restored surface morphology. An enhanced T50 lifetime of the ink-jet-printed device at 1000 cd/m2 is improved from 26 to 127 h, which converted to a long T50 lifetime of 8013 h, when operated at 100 cd/m2.
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CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Shiqiang Fu,Jiahao Wang,Xiaohui Liu,Haobo Yuan,Zuxiong Xu,Yongjin Long,Jing Zhang,Like Huang,Ziyang Hu,Yuejin Zhu
CsPbI 2 Br all-inorganic perovskite has attracted considerable attention due to its high thermal stability and suitable bandgap, while the unsatisfactory crystallization quality and moisture instability significantly hinder its further application. Herein, a novel multifunctional liquid additive, 2-hydroxyethyl methacrylate (HEMA), is introduced into the CsPbI 2 Br precursor to ameliorate the above issues. Our results demonstrate that the functional groups of HEMA can interact with perovskite precursor, thus improving crystallization and passivating defects at the same time, and leading to a champion power conversion efficiency of up to 16.13%. Importantly, HEMA molecule in perovskite films will polymerize to a hydrophobic polymer at grain boundaries through breaking C = C bonds during the high temperature annealing process (160 °C). Moreover, this multifunctional liquid additive strategy endows perovskite films with promoted moisture tolerance by crosslinking perovskite grains and blocking moisture penetration, thus the unencapsulated device maintains 78% of its initial efficiency after aging at 30% relative humidity for 1000 h. These results demonstrate that the additive engineering with multifunctional molecule is applicable strategy for developing CsPbI 2 Br all-inorganic perovskite solar cells with both high efficiency and stability.
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高影响因子
SOLAR ENERGY
·
2021
·
IF 5.742
Jixi Wang,Yangbiao Liu,Xiudi Xiao,Zhuoneng Bi,Yuan Lu,Guizhang Sheng,Xuesong Cai,Yanqing Zhu,Xueqing Xu,Gang Xu
All inorganic perovskite solar cells (PSCs) have been demonstrated to get tremendous interest recently owing to their better thermal stability. Nevertheless, some CsPbI 2 Br films prepared at low temperature have lower quality compared to those annealing at high temperature. Herein, to obtain high performance PSCs, a simple post-treatment strategy is presented by spin coating acetylacetone (AA) solution on the CsPbI 2 Br films. The AA treatment can reduce the density traps on the CsPbI 2 Br films surface and enlarge the size of grains, resulting in enhanced performance PSCs. After optimizing surface treatment, the devices based on low-temperature-processed CsPbI 2 Br with AA treatment achieved a power conversion efficiency (PCE) of 14.43%. The better CsPbI 2 Br films quality and interface contact of hole transport layer (HTL)/CsPbI 2 Br result in better device stability. Therefore, it could be a promising post treatment method for enhancing the performance of PSCs by introducing AA on the perovskite surface.
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ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Cong Geng,Yahong Xie,Peng Wei,Haichao Liu,Yue Qiang,Yi Zhang
Hole transporting material (HTM)-free carbon-based perovskite solar cells (C-PSCs) have been regarded as one of the most promising solar cell systems owing to their superior long-term stability and low cost. However, using commercial conductive carbon (CC) paste to prepare carbon electrode (CE) usually leads to a large number of defects at the perovskite/CE interface, often resulting in a low fill factor (FF) and poor photoelectric conversion efficiency (PCE). In this paper, by pyrolyzing ZIF-67 and etching with HCl, the Co-NC(HCl) composite with a large specific surface area are prepared. Combining this material with CC paste in different proportions, a series of HTM-free PSCs structured as FTO/SnO 2 /perovskite/CE are fabricated. Our experimental results demonstrate that the incorporation of Co-NC(HCl) composite efficiently improves interface performance of perovskite/CE, suppresses charge recombination and promotes hole extraction, consequently enhancing the photovoltaic performance of the C-PSC. In particular, the maximum PCE of 10.72% has been achieved in the ambient atmosphere, achieving 43% increasing over the pure CC-based device. The improved performance can be attributed to the significant effect of morphological structure of Co-NC(HCl) composite and the synergistic effect of Co-N co-doping on the performance of C-PSCs.
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Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 37
·12865-12875
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IF 7.059
Pan Shu,Xiaofei Cao,Yongqiang Du,Jiankui Zhou,Jianjun Zhou,Shengang Xu,Yingliang Liu,Shaokui Cao
The fiber-shaped resistive random access memory (RRAM) is an important subject for flexible wearable electronic textiles. The investigation of the resistive switching (RS) performance of the materials in the basic storage unit (crosspoint) of a flexible fibrous crossbar is very significant for realizing flexible wearable memories. In this work, fibrous crosspoint RRAM devices, abbreviated as FCPe-RRAMs, have been fabricated on the basis of organic–inorganic halide perovskite MAPbI3. Herein, a functional Al@MAPbI3 fiber is first prepared via a simple dip-coating method, in which the low-temperature solution processing method and cheap raw materials are conducive to the future large-scale and low-cost production. By optimizing the preparation conditions for MAPbI3, a pinhole-free, compact and uniform perovskite film is deposited on the bare Al fiber. Then, the FCPe-RRAM devices with a configuration of Al@MAPbI3/Al are assembled on a homemade holder by perpendicularly crossing the bare Al fiber and the functional Al@MAPbI3 fiber at a certain bending angle. The FCPe-RRAM devices exhibit a bipolar RS behaviour. The highest ON/OFF ratio reaches up to approximately 106 in the FCPe-RRAM devices, together with a low SET/RESET voltage (+1.66 V/−0.47 V) and a long retention time (>104 s). The FCPe-RRAM devices also exhibit excellent reproducibility and operational uniformity, which are important for practical applications in mass production. The investigation of the RS mechanism suggested that the FCPe-RRAM devices follow the mechanism of conductive metallic filament formation by the generated electrons with the help of thermionic emission. This work reveals the potential promising applications of FCPe-RRAM devices in flexible wearable memories with high storage density.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Dandan Lu,Keyang Yin,Ya Zhao,Zelin Gao,Nicolas Godbert,Hongmei Li,Hongguang Li,Jingcheng Hao
The synthesis of carbon dots (CDs) has attracted much attention in recent years. In this article, alkylated, blue-emitting CDs are prepared from dodecylamine through pyrolysis in differently substituted benzene solvents. The influences of the solvent on the size, yield and fluorescence quantum yield of the CDs have been investigated in detail. Overall, eight solvents were probed. It was found that the presence of halogen atom(s) in the solvent structure is beneficial for the production of the CDs, as seen from the poor yields of the CDs obtained in methylated benzenes. For the three mono-substituted halogenated benzenes with Cl, Br, I, as the atomic number of the halogen atom increases, hence increasing the resulting polarizability of the medium, the quantity of CDs obtained after pyrolysis also increases. For the two dichlorobenzenes probed, only the ortho-substitution is advantageous for the production of the CDs. The major quantity of CDs was obtained in iodobenzene (∼26 %) while the highest fluorescence quantum yield was observed for CDs prepared in bromobenzene (∼24 %), which is almost 4 times and 3 times that of the CDs developed in the old strategy using chlorobenzene as a solvent. Not only the change of the solvent tunes the photophysical properties of the CDs, it also alters their chemical structure. While the mono-substituted solvent is conducive to CDs with enriched C = O, the di-substituted one facilitates instead the formation of C-O. The possible interaction between the alkylamine and the solvent during pyrolysis was probed by adding lewis base and lewis acid to the system. Evidence of the occurrence of a process similar to Friedel-Crafts alkylation has been found. Our research illustrates new synthetic pathways and mechanism analysis for the preparation of CDs.
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