最新刊期
卷 41 ， 期 5 ， 2020
- 摘要：Perovskite solar cells (PSCs) based on organic metal halide perovskite materials as photoactive layer have been obtained a certified power conversion efficiency of 25.2% and are considered to be one of the most commercially viable solar cells. In the device structure of PSCs, the electron transporting layer is one of the most basic components. The selection of the electron transporting materials is closely related to the film quality of the photoactive layer, the rapid extraction of interface charge and the matching of bandgaps. Therefore, the electron transporting materials play an important role in the regulating the photovoltaic performance and stability of PSCs. This paper reviews and summarizes the research progress of metal oxide electron transporting materials applied in PSCs, emphasizes the nanostructure and preparation process, photoelectric characteristics and classification, doping and surface modification of metal oxide electron transport materials, and looks forward to its future development.关键词：perovskite solar cells;metal oxide electron transporting materials;doping;interface modification332|377|3更新时间：2020-09-21
Invted Review
- 摘要：Inorganic luminescent nanomaterials have shown great promise in various fields due to their unique optical properties. Base on the authors' research experience, we herein offer our perspectives for researchers in inorganic luminescent nanomaterials, including focusing on the frontiers of so-called "pain points" and "unpopular topics" of this field, and facing the national major demands. We encourage researchers in this field to move out of their own comfort zones and devote themselves to the distinctive areas, in an effort to promote the sustainable development of inorganic luminescent nanomaterials.关键词：luminescent materials;nanomaterial;rare earths;photoluminescence;nano-bioprobe395|192|1更新时间：2020-09-21
- 摘要：In recent years, rare earth luminescent materials, as the core component of lighting, display and signal detector, have been developed rapidly. China has been the largest producer and consumer of rare earth luminescent materials for many years. The article introduces the developing situation of rare earth luminescent materials, and points out the development trends in the fields of ultro-high color gamut display, healthy lighting of full spectrum and phosphor converted near infrared light source. Presently, there are some core problems for domestic industry, such as weakness of original innovation ability, poor goal orientation and lack of industry-univerisity-research collaborative innovation. To solve these problems, we propose to build a collaborative innovation technology platform by gathering superior strength, and dual drive forces of technological innovation and terminal application demand, which realize the leap-forward road from "following and running" to "leading".关键词：luminescent material;patent;application;collaborative innovation396|343|6更新时间：2020-09-21
- 摘要：The root of technological innovation is based on the improvement of basic scientific research, and the /peakthrough from "0 to 1" requires long-term accumulation and inspiration. The paper describes the idea and material design for discovering the new phenomenon of pressure-induced emission.关键词：pressure-induced emission;halide perovskite materials;self-trapped exciton320|340|0更新时间：2020-09-21
40th Anniversary Special Column——Young Scientist on The Road
- 摘要：BaGa2Si2O8:Eu2+, Eu3+, Pr3+ phosphors with multi-modes luminescence were prepared by solid-state method. Meanwhile, the afterglow luminescence properties of phosphors are significantly increased by adding a proper content of Pr3+. It demonstrates that the phosphors show photoluminescence and afterglow luminescence with different colors under 254 nm or 365 nm excitation, indicating the feature of multi-mode luminescence. Meanwhile, the afterglow luminescence of the phosphors also shows different decay time. According to these luminescent features, we choose the appropriate phosphors to make a series of luminescent patterns. The typical examples demonstrate that the multi-mode luminescent characteristic of the patterns can be used in anticounterfeiting. Moreover, based on its characteristic of different afterglow decay time, we can also design the dynamically changing luminescent patterns to increase the security level of anti-counterfeiting and encryption.关键词：phosphor;luminescence properties;anticounterfeiting;encryption229|227|4更新时间：2020-09-21
- 摘要：In this paper, a series of single-host phosphors NaLa1-x-yMgWO6:xDy3+/yBi3+ (x=0.01, 0.02, 0.04, 0.06;y=0.01, 0.02, 0.04, 0.06) were prepared by high temperature solid state method. By the optimization of Dy3+/Bi3+ double codoping concentration, the doping of Bi3+ ions can not only effectively enhance the luminescence intensity of phosphors, but also achieve the tune of luminescence color. The fluorescence lifetime of Bi3+ for NaLaMgWO6:xDy3+/0.02 Bi3+ samples gradually decreased with the increased concentration of Dy3+ ions (1%-6%), which proves strongly the presence of energy transfer process from Bi3+ ions to Dy3+ ions in NaLaMgWO6:Bi3+/Dy3+ phosphors. According to the calculation of the electric multipole interaction formula, we can know that the energy transfer process of Bi3+→Dy3+ is a dipole-dipole interaction and the energy transfer efficiency of the optimal Bi3+/Dy3+ doped samples was calculated to be 42.67%. Under the effective excitation of the UV-light (ultraviolet light), NaLaMgWO6:Bi3+/Dy3+ phosphor can realize the emission of white light by changing the amount of Dy3+ ions. The research proves that NaLaMgWO6:Bi3+/Dy3+ phosphor is a kind of white light emitting material with potential application prospects.关键词：bismuth/dysprosium ion co-doping;high temperature solid state;energy transfer;NaLaMgWO6288|263|5更新时间：2020-09-21
- 摘要：A series of blue-emitting phosphors Gd2-xMgTiO6:xBi3+(0.002 5 ≤ x ≤ 0.015) were synthesized by high-temperature solid state method, and the corresponding morphology, crystal structure, photoluminescence properties and thermal stability were investigated. The scan electron microscope(SEM) test predicted that the samples Gd2MgTiO6:Bi3+ possessed a large particle size distribution with the particle size ranging from 1 μm to 5 μm. The X-ray diffraction (XRD) analysis showed that the Bi3+ ions successfully doped into host lattice Gd2MgTiO6 with no other impurity phase existed. The photoluminescence properties stated that the blue emitting phosphors Gd2MgTiO6:Bi3+ presented a single narrow emission peak located at about 418 nm assigned to the 1S0→3P1 transition in the range from 385 nm to 500 nm in the excitation of 375 nm, which helped to avoid light reabsorption. Moreover, when the doping concentration of Bi3+ ions is 0.007 5, the emission intensity reaches the maximum. The sample Gd1.9925MgTiO6:0.0075Bi3+ with best photoluminescence properties exhibited a Commission Internationale De I'eclairage(CIE) coordinates of (0.162 9, 0.036 4) in blue-light area with an impressive color purity up to 96.42% and an impressive average lifetime of 11.29 ms. In addition, the thermal stability of sample Gd1.9925MgTiO6:0.0075Bi3+ was relatively higher than that of similar blue-emitting phosphors in the literature. These results indicated that sample Gd1.9925MgTiO6:0.0075Bi3+ is a kind of blue-emitting component for W-LEDs with excellent luminescence and thermal stability.关键词：W-LEDs;high color purity;Gd2MgTiO6:Bi;blue emitting phosphor181|193|2更新时间：2020-09-21
- 摘要：Recent years, Up-conversion(UC) luminescence exhibits potential application in temperature measurement based on FIR(fluorescence intensity ratio) technique, which has drawn considerable attention. Lanthanum oxyfluoride(LaOF) inherits the advantage of low lattice phonon energy, and exhibits superior thermal and chemical stability, showing efficient UC luminescence. Thus, limited attention has been paid to the temperature sensing characteristics of Er3+/Yb3+ co-doped LaOF. In the present work, rhombohedral LaOF:Er, Yb phosphors are prepared using hydrothermal method. The structure and fluorescence properties are characterized by X-ray diffraction, SEM and fluorescence spectra. Hexagonal LaF3 is prepared using hydrothermal method at 120℃. After annealing at 1 000℃, rhombohedral LaOF is obtained. The agglomerated particle crystallizes into one larger particle in the range of several micron following annealing. Excited by 980 nm, the characteristic emission from the Er3+ ion is observed, including two green emission bands and one red emission, 2H11/2→4I15/2 and 4S3/2→4I15/2 as well as 4F9/2→4I15/2 transitions. Energy transfer between Er3+ and Yb3+ is confirmed because of two-photon process, resulting in upconversion emissions. Finally, the optical temperature sensing properties of R-LaOF:Yb, Er are investigated. The results suggest that R-LaOF:Er, Yb exhibits intense emission and high sensitivity. Its maximum relative sensitivity SR and absolute sensitivity SA are 0.037 K-1and 0.004 3 K-1 respectively in the temperature range of 150-400 K, suggesting it is a potential candidate in temperature sensing.关键词：upconversion emission;temperature sensing;fluorescence intensity ratio technique;sensor sensitivity181|343|5更新时间：2020-09-21
- 摘要：All-inorganic perovskite CsPbX3 nanocrystals have excellent photoelectric characteristic, such as adjustable luminescence with narrow full-width at half maximum in visible light, and their devices being easily processed with high stability. They have been widely used in optoelectronic devices. The advances of all-inorganic perovskite CsPbX3 nanocrystals will be reviewed in this paper. First, we introduced the molecular structure, size effect, luminescence characteristics and photocatalysis of CsPbX3 nanocrystals. Then the synthesis methods, stability and specific photoelectric applications were described. Finally, we summarized and prospected the problems and future development of CsPbX3 nanocrystals.关键词：all-inorganic perovskite;CsPbX3;nanocrystals331|446|6更新时间：2020-09-21
- 摘要：In recent years, Cs2SnI6 has been used in solar cells as a non-toxic and stable new perovskite material. The power conversion efficiency(PCE) has exceeded 8.5% since the PCE of 1% was first reported in 2014, making the perovskite solar cells the best potential candidate of the new generation solar cells to replace the lead-based perovskite solar cells in the future. The electronic structures and absorption spectra of the defect perovskites Cs2SnI6 were investigated by first-principles calcuation using PBE and HSE06 hybrid functional. The results show that optic band gaps based on HSE06 are 1.023 eV for Cs2SnI6 at the Γ-point, illustrating a direct band gap. Electronic structures calculations show that the conduction band mainly consists of hybridization between the halogen p orbitals and Sn 5s orbitals, whereas the valence band is composed of the halogen p orbitals.The Cs2SnI6 film is adopted as a light absorber layer for a lead-free perovskite solar cell and the power conversion efficiency 26.1% with open-circuit voltage of 0.91 V and short-circuit current of 32.86 mA/cm2 is realized by optimizing the perovskite absorber thickness of 10 μm. It provides a reference for the experimental preparation of high-efficiency Cs2SnI6 perovskite solar cells.关键词：first-principles;perovskite solar cells;electronic structure;optical properties283|122|1更新时间：2020-09-21
- 摘要：The metal halide perovskite CsPbBr3 films have excellent optical properties, which is an ideal candidate material for full-color display as a wavelength conversion layer in liquid crystal display(LCD). In order to achieve efficient photoconversion from blue to green, CsPbBr3 micron-thick films have been prepared by the pulse laser deposition technique. And the morphology, structure, optical properties are investigated by means of SEM, XRD, and UV-Vis spectrum, respectively. Then the CsPbBr3 micrometer-thick film is deposited on the blue light emitting diode whose emission wavelength is 460 nm, and the performance of light conversion is measured. The results show that the obtained CsPbBr3 films are composed of highly (100)-oriented columnar crystal and the film thickness increases in proportion to the number of laser pulse. When the deposited CsPbBr3 film thickness is 2.252 μm, a pure and effective green light emission is achieved under the excitation of blue light(460 nm). In addition, the intensity of photoluminescence(PL) does not decrease significantly when the samples are placed in an air atmosphere(temperature 20℃, humidity 25%) for 18 days.关键词：pulse laser deposition;thick-films;photoconversion;liquid crystal display;green273|145|0更新时间：2020-09-21
- 摘要：In order to implant ZnO nanostructures in new optoelectronic devices such as solar cells, it is necessary to tailor and control the ZnO nanorod arrays' morphology, optical and electrical properties. The ZnO nanorod arrays were fabricated by electrodeposition. In(NO3)3 and NH4NO3 were incorporated in the basic Zn(NO3)2 electrolytes. The characterizations of the ZnO nanorods including the scanning electron microscopy, tranmission spectra, reflection spectra and photoluminescence were used to analyze the ZnO nanorods' morphology, optical and electrical properties. The ZnO nanorods' average diameter was decreased from 57 nm to 30 nm with increasing the In(NO3)3 concentration. The reduce of the ZnO nanorods' density resulted in the increase of the distance between nanorods to 41 nm. The ZnO nanorods' optical band showed blue shift from 3.46 eV to 3.55 eV. The Stokes shift in ZnO nanorods was reduced from 198 meV to 154 meV with the increase in the In(NO3)3 concentration, indicating the suppression of the nonradiative recombination. The ZnO nanorods' physical properties such as the diameter, density, distance, transmission, reflection, optical band gap energy, near band edge emission and nonradiative recombination can be controlled and tailored by incorporating In(NO3)3 and NH4NO3 in the basic Zn(NO3)2 electrolytes.关键词：ZnO;indium nitrate;electrodeposition;band gap blue shift;nonradiative recombination151|104|2更新时间：2020-09-21
Synthesis and Properties of Materials
- 摘要：Ratiometric fluorescence sensors have shown great application potential in fields of food safety, metal ion detection, environmental pollution analysis, etc, due to its strong anti-interference ability and high sensitivity. As a new fluorescent material, carbon dots (CDs) have excellent photoluminescence property and low toxicity and the surface is easy to be functionalized, which have become a good choice to build ratiometic fluorescent sensor. In this paper, the recent research progresses of CDs-based ratiometric fluorescence sensor in the detection field are reviewed, and the fluorescence mechanism of carbon dots is mainly outlined. The CDs-based ratiometric fluorescence sensors are classified and summarized based on different applications of carbon dots. Finally, the difficulties and problems to be overcome in this field are put forward, and the development direction of the application of CDs-based ratiometric fluorescence sensor for analytic detection is prospected.关键词：ratiometric sensor;carbon dots;detection mechanism;visual detection559|424|8更新时间：2020-09-21
- 摘要：In this paper, we propose a technical route to prepare full-color display device based on blue Micro-LED array and environmental friendly InP/ZnS quantum dots. We design the new structure of full-color Micro-LED display device. We design and prepare InP/ZnS quantum dots color conversion layer which matches the blue Micro-LED array. In our new structure of full-color Micro-LED device, InP/ZnS quantum dots color conversion layer is inverted and has no direct touch with the blue Micro-LED array which can relieve the adverse effect on the PL characteristic of InP/ZnS quantum dots material. In order to prepare quantum dots layer with uniform film and uniform luminescence, flexible PDMS polymer layer is embedded into the substrate of the color conversion layer to eliminate coffee-ring effect. At the same time, the patterned 500 nm longwave filter film embedded into the substrate of the color conversion layer can suppress blue light emission which can improve the color purity of the InP/ZnS quantum dot pixel luminescence unit. Finally, a 16×16 InP/ZnS quantum dots color conversion layer with a pixel pitch of 90 μm was prepared experimentally. Based on the design and preparation method, the full-color Micro-LED device can be prepared with lower cost and higher efficiency.关键词：micro-LED;InP/ZnS quantum dots material;color conversion layer;full-color display device301|279|2更新时间：2020-09-21
Device Fabrication and Physics
- 摘要：The radiation effects of MBE grown GaAsN/GaAs quantum well irradiated by 1 MeV electron with different dose (1×1015, 1×1016 e/cm2) and post thermal annealing (650, 750, 850℃) have been studied.The degradation mechanism and annealing effects were discussed by Mulassis simulation and GaAs energy bandgap model. The results show that the GaAsN/GaAs quantum well PL intensity significantly decreased with the increase of electron does. The PL intensity of the GaAsN GaAs quantum well decayed to 85% and 29% of the initial value after electron irradiation with doses of 1×1015 e/cm2 and 1×1016 e/cm2, respectively. The PL intensity of GaAsN/GaAs quantum well returned to original value after annealing at 650℃ for 5 min, and the bandgap of the material remained unchanged. The PL intensity of GaAsN/GaAs samples decreased as the annealing temperature increased after annealed at 750℃ and 850℃ for 5 min, and the bandgap blue shifted about 4 nm due to the diffusion of N atoms from GaAsN quantum well to GaAs barrier layer. The increase of annealing temperature did not cause additional blue shifts of the band gap. This was due to the further increase in temperature, which caused new N-As defects, suppressed N-atom diffusion, and degraded the optical properties of GaAsN/GaAs quantum well.关键词：dilute nitride;photoluminescence;electron irradiation;GaAsN;annealed231|129|1更新时间：2020-09-21
- 摘要：We assemble typical micro photonic circuits based on rhodamine B doped polymer microfibers(RhB doped PMFs), such as Y beam splitter and microfiber-ring cavity coupling structures. Through the tapered fiber, a 532 nm incident light is launched into the RhB doped PMFs and excited the fluorescence simultaneously. The propagation distance of the energy could be increased by moving the tapered fiber along the PMF. We analyze the relationship between the propagation distance and the output intensities of the coupling structures. The results show that the energy distribution in the doped PMF could be visualized according to the fluorescent path in the circuit. Along the straight part of PMF, the energy propagates decreasingly with a periodic oscillation. Significant phase jump could be observed at the curved part. Moreover, the output intensity of the circuit also has a periodic variation with the increasing propagation distance. By simply moving the tapered fiber in a half period, the split ratio of the Y splitter could be adjusted from 1.3 to 2.4 (within 2 μm) while the peak-to-valley ratio of the output intensity in the ring cavity structure could reach 2.1 (within 6 μm). For the fluorescence excited by the tapered fiber in the coupling structure, we could directly observe the energy distribution in real-time from optical far field. A large changing range of the output intensity could be realized by simply moving the tapered fiber within a few micrometers. Our results demonstrate a visible and simple approach for photonic circuit fabrication and adjustment.关键词：polymer microfiber;fluorescent doping;energy observation;energy adjustment;photonic circuit187|144|0更新时间：2020-09-21
- 摘要：In order to solve the problem that the stimulated Brillouin scattering fast light which occurs in the high absorption region decays rapidly, fast light via stimulated Brillouin scattering at double Brillouin gain line in an optical fiber is described and numerically simulated. The simulation results show that the fast light occurs between the double gain peaks induced by two pump waves when the frequency separation factor is at the range of 1-5.25, and the maximum time advancement is up to 25 ps between the doublet Brillouin lines when the frequency separation is 1.75. The double gain peaks can be observed when the frequency separation factor is larger than 0.596. The three-order dispersion (TOD) can complete compensation in the frequency separation factor range of 1-5.25. The dispersion relation can be represented by the normalized dispersion length Lm. As the separation factor is 2.42, the Lm of TOD is infinite that expressed the TOD being fully compensated. The pulse broadening factor is 0.986 and the time advancement is 13.52 ps at the separation factor of 2.464. The pulse broadening factor is close to 1 when the frequency separation factor being larger than 2.464, and the time advancement is less than 13.52 ps. The research conclusions have certain theoretical significance for the realization of fast light in the Brillouin gain region, and have theoretical reference for designing optical devices based on stimulated Brillouin scattering fast light.关键词：fiber optics;stimulated Brillouin scattering;double-line pumps;fast light136|325|0更新时间：2020-09-21
- 摘要：Graphene has a wide range of applications in the field of optoelectronics, but its low absorption limits its application in some aspects. In order to improve the absorption performance of single-layer graphene, a composite structure composed of graphene and photonic crystal heterostructure was designed based on previous studies. The influence of external magnetic field, Fermi energy and design wavelength on the absorption spectrum of graphene was numerically studied by 4×4 transfer matrix method. The results show that the designed optical structure not only keeps the original broad absorption band of graphene, but also increases several narrow absorption bands. The number of narrow absorption bands can be adjusted by changing some structure parameters. Due to the magneto-optic effect, the absorption properties of graphene exhibit a certain magnetic circular dichroism. For each absorption band, the absorption of left-handed circularly polarized light is usually higher than that of right-handed circularly polarized light. However, by adjusting the external magnetic field and Fermi energy, each absorption band can have an absorption of more than 99%, and under certain conditions, a near-perfect 100% absorption can be achieved. The results provide a useful reference for the design of graphene-based devices in the field of optoelectronics.关键词：graphene;light absorption;photonic crystals;magnetic fields;transfer matrix method225|163|3更新时间：2020-09-21
Luminescence Applications and Interdisciplinary Fields
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