- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Tunable spectrum resemblance of LED lights for improving the photosynthetic action of Chinese Cabbages
摘要： To increase efficiency, and reduce energy loss and waste, we propose to improve the photosynthetic action spectrum resemblance (SRPAS) of LED light with the absorption spectra of the fresh leaf, for accelerating the growth of Chinese Cabbages. Eight spectral LED lights were adopted to irradiate Chinese Cabbages under 150 μmol·m-2·s-1 for a 16 hd-1 photoperiod. Of these, under the irradiation of blue + broad red + more yellow (BRY2) light with high spectrum resemblance of 75%, the fresh weight and dry weight are 5.1times and 3.0 times, respectively, and the leaf area and leaf number are 1.7 times, as high as under the blue light. The results demonstrate that the optimized LED light can be presumed to have the highest spectrum resemblance (SRPAS) with the absorption spectra of Chinese Cabbages, and the highest energy-conversion efficiency. These conclusions may be of great benefit to further assess and find either an ideal light applied for plant growth or design of better light sources for growing different plants.
关键词： Absorption spectrum,Photosynthetic action spectrum resemblance,LED lighting,Growth and morphology,Chinese Cabbages
更新于2025-09-23 15:21:01
-
Computational determination of structural, electronic, optical, thermoelectric and thermodynamic properties of hybrid perovskite CH3CH2NH3GeI3: An emerging material for photovoltaic cell
摘要： Owing to high power conversion efficiency and low-cost, methyl-ammonium lead-based halide (viz. CH3NH3PbI3) Perovskites have been emerging as the innovative candidate in the development of optoelectronic devices. However, the toxic lead in these materials is a major hurdle in its commercialization. Thus, there is an urgent need to replace lead with an appropriate element. Ethyl-ammonium based lead-free hybrid halide perovskites may be an alternative photovoltaic (PV) absorber material with appropriate band gap, high stability and non-toxic properties. Herein, we have investigated structural, electronic, optical, thermoelectric and thermodynamic properties of ethyl-ammonium germanium iodide (CH3CH2NH3GeI3 or EAGeI3) by full-potential augmented plane wave (FP-LAPW) method as implemented in the WIEN2k code within the density functional theory (DFT). In this paper, we have found that EAGeI3 has direct band gap of 1.3 eV and high absorption coefficient greater than 104 cm-1 and indicating its suitability as PV absorber material. We have also calculated thermoelectric coefficients as a function of carrier concentration, chemical potential and temperature. The thermodynamic calculations have been done within the quasi-harmonic approximation. As EAGeI3 has been studied first time for PV applications, the present study may open a new vista for more exhaustive experimental and theoretical investigations in search of non-toxic and eco-friendly PV materials.
关键词： absorption coefficient,Seebeck Coefficient,Ethyl-ammonium based hybrid perovskite,figure of merit,band gap
更新于2025-09-23 15:21:01
-
Ternary Organic Solar Cells Based on two Non-fullerene Acceptors with Complimentary Absorption and Balanced Crystallinity
摘要： The ternary blend structure has been demonstrated as an effective approach to increase the power conversion efficiency of organic solar cells. An effective approach to enhance the power conversion efficiency of ternary solar cells is based on two non-fullerene acceptors with complimentary absorption range and balanced crystalinity. In this work, by introducing a high crystallinity small-molecule acceptor, named C8IDTT-4Cl with appropriate alkyl side chains into a low crystalline blend of conjugated polymer donor PBDT-TPD and fused-ring electron acceptor ITIC-4F. A ternary device based on the blend PBDT-TPD:ITIC-4F:C8IDTT-4Cl exhibits a best power conversion efficiency of 9.51% with a simultaneous improvement of the short-circuit current density to 18.76 mA cm-2 and the fill factor up to 67.53%. The absorption onset for C8IDTT-4Cl is located at 900 nm, so that the well complementary light absorption is beneficial to the photocurrent. In addition, the existence of high crystallinity C8IDTT-4Cl in the ternary device is found helpful to modulate crystallinity, improve heterojunction morphologies and stacking structure, therefore to realize higher charge mobility and better performance.
关键词： Non-fullerene Acceptors,Ternary Organic Solar Cells,Power Conversion Efficiency,Complimentary Absorption,Balanced Crystallinity
更新于2025-09-23 15:21:01
-
Two dimensional temperature measurement characteristics in pulverized coal combustion field by computed tomography-tunable diode laser absorption spectroscopy
摘要： Two dimensional temperature and concentration distributions are important parameters for pulverized coal combustion used for power plant to understand the combustion field and develop the high efficient combustion technologies. However, it is difficult to measure two dimensional temperature and concentration in pulverized coal combustion field using conventional measurement technologies because pulverized coal combustion produces lots of dust and strong emission from its flame. This paper focused on the application of two dimensional temperature measurement method based on the combination of computed tomography and tunable diode laser absorption spectroscopy using absorption spectra of water vapor at 1388nm and 1343nm for each laser scanning using direct absorption spectroscopy, which show the better characteristics of spatial-temporal resolution, fast response, high sensitivity, self-calibration and optical accessibility. Accuracy of temperature measurement using tunable diode laser absorption spectroscopy was improved by applying the corrected spectroscopic database. Computed tomography reconstruction accuracy of 16 laser-paths configuration was evaluated using sum of squared difference (0.001) and zero-mean normalized cross-correlation (over 0.991), which presented the consistent temperature between assumed and reconstructed distributions. This developed computed tomography-tunable diode laser absorption spectroscopy was successfully applied to pulverized coal flame for two dimensional temperature measurement with 1 ms temporal resolution for time-series two dimensional temperature measurement in the range of 300K-2500K. The rationality was demonstrated by comparison of pulverized coal flame and Methane-Air flame temperature distributions due to the main heat release produced by methane fuel. Its applicability to pulverized coal combustion field will be benefit for optimal operation control and combustion efficiency improvement by combustion organization or new design of combustion system.
关键词： Power plant,Pulverized coal combustion,Computed tomography (CT),Tunable diode laser absorption spectroscopy (TDLAS),Two dimensional temperature measurement
更新于2025-09-23 15:21:01
-
Manipulating Optical Absorption of Indium Selenide Using Plasmonic Nanoparticles
摘要： In this work, we propose using periodic Au nanoparticles (NPs) in indium selenide-based optoelectronic devices to tune the optical absorption of indium selenide. Electromagnetic simulations show that optical absorption of indium selenide can be manipulated by tuning plasmonic resonance. The e?ect on the plasmonic resonance of the size, period of NPs, the thickness of silicon oxide, and the insulator spacer is systematically analyzed. A high absorption enhancement over the visible spectrum is achieved through systematic optimization of nanostructures.
关键词： optoelectronic devices,indium selenide,optical absorption,plasmonic nanoparticles,plasmonic resonance
更新于2025-09-23 15:21:01
-
Numerical analysis of earth-abundant Cu2ZnSn(SxSe1-x)4 solar cells based on Spectroscopic Ellipsometry results by using SCAPS-1D
摘要： Mixed chalcogenide CZTSSe with earth abundant elements, inexpensive, environmental-friendly and impressive photovoltaic performance is a promising absorber material for kesterite thin film solar cells of third generation. In this work, a numerical simulation of p-CZTSSe/n-CdS heterojunction solar cells have been presented using one dimensional Solar Capacitance Simulator. The influence of composition, absorber thickness, defect density and working temperature on Voc, Jsc, FF and power conversion efficiency has been investigated. The optimized cell shows 23.16% efficiency with a Voc ~ 0.724 V corresponding to 40% of the ratio.
关键词： Composition and Spectroscopic Ellipsometry,Absorption coefficient,CZTSSe,Thin film solar cell,Third generation,SCAPS,Efficiency
更新于2025-09-23 15:21:01
-
Thiazolo[5,4- <i>d</i> ]thiazole-based organic sensitizers with improved spectral properties for application in greenhouse-integrated dye-sensitized solar cells
摘要： Organic photosensitizers especially designed for producing semitransparent dye-sensitized solar cells (DSSCs) for greenhouse integration were prepared by introduction of different heterocyclic moieties into the thiazolo[5,4-d]thiazole-molecular scaffold. The aim was that of improving their light absorption capability in the green part of the visible spectrum while maintaining a good transparency in the blue and red regions, where the photosynthetic response is maximized. A short and efficient synthetic approach, featuring two consecutive C-H activation reactions in a one-pot procedure as key steps, was used. Based on their spectroscopic and electrochemical characterization, two of dyes prepared appeared especially suitable for greenhouse-integrated photovoltaics. The corresponding semitransparent DSSCs yielded 5.6-6.1% power conversion efficiencies, which were largely superior to those provided by other organic dyes previously proposed for the same application.
关键词： organic photosensitizers,light absorption,photovoltaic efficiency,dye-sensitized solar cells,greenhouse integration,thiazolo[5,4-d]thiazole,transparency
更新于2025-09-23 15:21:01
-
Crystal growth and spectroscopic investigations of Dy:YAlO3 and Dy,Tm:YAlO3 crystals for a??3a?ˉ??m laser application
摘要： Dy3+:YAP and Dy3+,Tm3+:YAP single crystals have been successfully synthesized by Czochralski (CZ) method aiming for ~3 μm emission. The optical absorption and emission features of both crystals were studied in detail. A narrow and weak absorption band around 800 nm as well as an upconversion emission under the excitation of 802 nm in Dy3+:YAP crystal along with a weak ~3 μm emission were observed, indicating that Dy3+:YAP crystal is not suitable for direct pumping under 800 nm excitation. Tm3+ ion was introduced as a sensitizer for enhancing ~3 μm emission and found that co-doping with Tm3+ greatly improved the absorption capacity around 800 nm. An enhanced ~3 μm emission was observed in Dy3+,Tm3+:YAP crystal under 795 nm excitation. The energy transfer mechanisms between Dy3+ and Tm3+ ions and the energy transfer micro-parameters were discussed. Higher values of microscopic energy transfer constants between Dy3+ and Tm3+ ions were obtained, proving Tm3+ ion act as an effective sensitizer for Dy3+ ion in YAP crystal. Following the obtained optical results, Dy3+,Tm3+:YAP crystal could be a promising medium for 3 μm laser operation under 795 nm laser diode for practical applications.
关键词： optical absorption,energy transfer micro-parameters,3 μm emission,MIR laser,Dy3+,Tm3+:YAP crystal
更新于2025-09-23 15:21:01
-
Semi-Transparent Organic Solar Cells Enabled by Sequentially Deposited Bilayer Structure
摘要： Semi-transparent organic solar cells (ST-OSCs) have been regarded as a promising candidate for building integrated photovoltaics (BIPV). In general, most of the ST-OSCs are based on bulk heterojunction (BHJ) structure, in which, the morphology of BHJ film must be delicately optimized. In this work, we introduce sequentially deposited bilayer structure into ST-OSCs by using PTB7-Th:IEICO-4F combination. The adoption of bilayer structure not only simplifies the device optimization, it is also found that, as donor and acceptor are separately deposited, the power conversion efficiency (PCE) of bilayer ST-OSCs can be improved by simply increasing the thickness of IEICO-4F, which has strong near infrared absorption but weak visible light absorption, without significantly affecting the average visible light transmittance (AVT) of device. However, in BHJ structure, the increase in BHJ film thickness unavoidably enhances the donor absorption in visible light region, leading to a tradeoff between PCE and AVT in BHJ structure ST-OSCs. Eventually, the bilayer structure device exhibits better overall performance than BHJ structure device, e.g. PCE of 8.5% for bilayer structure vs PCE of 8.1% for BHJ structure with AVT around 21%. Our findings indicate that the sequentially deposited bilayer structure, aside from its easy processing characteristic, also has great potential for preparing high performance ST-OSCs.
关键词： simplified processing,increased infrared absorption,organic solar cells,bilayer structure,semi-transparent
更新于2025-09-23 15:21:01
-
Effect of Uncontrollable Impurities on the Absorption Spectrum of a NaGd(WO4)2 Laser Crystal
摘要： Three NaGd(WO4)2 single crystals were grown by the Czochralski method using charges of different chemical purity. The impurity compositions of the grown crystals were analyzed by inductively coupled plasma mass spectrometry. The optical absorption spectra of the crystals were measured, and the effect of uncontrollable impurities on their optical properties and color was analyzed. The green color encountered in NaGd(WO4)2 crystals in some cases was shown to be due to the uncontrollable impurities of d elements, among which the chromium impurity had the most significant effect.
关键词： optical absorption,impurity purity,color centers,single crystals,zinc tungstate,ytterbium
更新于2025-09-23 15:21:01