- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Luminescence quenching properties of Sr2Ga2GeO7: Pr3+ with and without traps participation
摘要： Thermal quenching has been extensively regarded as one of the most signi?cant challenges that limits the application of phosphors in today's world. Further e?ort is urgently required to understand the mechanism of thermal stability for achieving the improved performance of these phosphors. Sr2Ga2GeO7: Pr3+ has been synthesized by the conventional high temperature solid state reaction. A dominant green emitting is presented for the partial energy transition quenching process of the 3P0→3H4 emission. The defect states structure is improved via the introducing of co-solvents, and the thermal stability of 1D2→3H4 and 3P0→3H4 levels can be further adjusted. The intervalence charge transfer (IVCT) and traps are introduced to explain the luminescence quenching properties of Sr2Ga2GeO7: Pr3+. The synergy of various models will provide a new idea for improving the luminescence stability of phosphors in the future.
关键词： Partial energy transition,Thermal quenching,IVCT,Mechanism
更新于2025-09-23 15:23:52
-
Vertical bifacial photovoltaics a?? A complementary technology for the European electricity supply?
摘要： Thanks to the two diurnal generation peaks, vertical bifacial photovoltaic power plants (VBPV) with a north-south axis represent an option to meet the challenges of a mismatch between electricity demand and the generation profile of conventional photovoltaic systems (C-PV). Despite this promising characteristic, it is hardly possible to assess the technical and economic properties of VBPV on the basis of existing studies. The present work is a contribution to close this gap. Among other things, the conducted analyses included electricity generation, market revenues, levelized costs of electricity (LCOE) and the cost-reducing effect of VBPV in a national electricity system. C-PV was used as a benchmark in all analyses. Electricity generation was simulated at twelve European sites in four countries. It has been found that above a latitude of 50° VBPV generates more electricity than C-PV. Due to the higher investments, VBPV had higher LCOE at all locations investigated. The results also showed that VBPV can generate higher revenues in electricity markets with a high share of C-PV capacity, but that these additional revenues are not yet sufficient to compensate for the higher investments. With an optimising electricity market model, it was also found that VBPV can contribute to reducing system costs in an electricity system with high shares of C-PV capacity. Against the background of the increasing importance of PV for the electricity supply of most European countries, these findings are of particular importance. In summary, it can be said that VBPV has significant potential at both the business and macro-economic level and that decision makers should promote the market entry of this technology.
关键词： Energy transition,Electricity market,System-friendly renewables,Electricity system costs,PV,Market value
更新于2025-09-19 17:13:59
-
Tuning opto-electronic properties of alkoxy-induced based electron acceptors in infrared region for high performance organic solar cells
摘要： Limitations of fullerene-based acceptors for organic solar cell have driven the scientific community to design and synthesize non-fullerene acceptors. In this regard, we have designed four new molecules designated here S1-S4 containing Alkoxy-Induced Naphtho-dithiophene donor unit and 2-(5,6-difluoro-2-methylene-3-xo-2,3-dihydrinden-1-ylidene)malonoitrile acceptor moiety attached with different bridge units. The electronic and optical properties of the designed molecules S1-S4 are compared with the recently reported reference molecule R. The bridge units are, thiophene (S1), 2-fluorothiophene (S2), 2-(thiophe-2-yl)thiophene (S3) and 2-(4-fluorothiophen-2-yl)thiophene (S4). The designed molecule S3 shows absorption maximum in near infra-red (NIR) region at 830.0 nm and 910.6 nm in gas phase and chloroform solvent, respectively. The energy gaps of designed molecules are lower than that of the reference R, which reveal high charge transfer for the designed molecules. Among all, S3 has the lowest energy gap (1.68 eV). Open circuit voltages (Voc) calculation are performed with well-known PTB7-Th donor. Voc of all the molecules are higher than R where the maximum Voc of 1.92V is calculated for S2. Low reorganization energies of our designed molecule reflect high charge transfer rate with respect to R. Among all designed molecules, S3 has the highest electron mobility.
关键词： Alkoxy induced,Reorganization energy,Transition density matrix,Non-fullerene acceptor,Thiophene,Charge Transfer,Open circuit voltages
更新于2025-09-19 17:13:59
-
The Role of Photovoltaics (PV) in the Present and Future Situation of Suriname
摘要： The aim of this paper is to give an overview of the energy sector and the current status of photovoltaic (PV) systems in Suriname and to investigate which role PV systems can play in this country’s future energy transition. At this moment, 64% of the power is available from diesel/heavy fuel oil (HFO) gensets while 36% is available from renewables namely hydroelectric power systems and PV systems. Suriname has renewable energy (RE) targets for 2017 and 2022 which already have been achieved by this 36%. However, the RE target of 2027 of 47% must be achieved yet. As there is abundant irradiance available, on an average 1792 kWh/m2/year and because several PV systems have already been successfully implemented, PV can play an important role in the energy transition of Suriname. In order to achieve the 2027 target with only PV systems, an additional 110 MWp of installed PV capacity will be required. Governmental and non-governmental institutes have planned PV projects. If these will be executed in the future than annually 0.8 TWh electricity will be produced by PV systems. In order to meet the electricity demand of 2027 fully, 2.2 TWh PV electricity will be required which implies that more PV systems must be implemented in Suriname besides the already scheduled ones.
关键词： photovoltaics systems,electric energy generation,energy transition,renewable energy,Suriname
更新于2025-09-11 14:15:04
-
Single Crystal Growth and Characterization of the Chalcopyrite Semiconductor CuInTe2 for Photoelectrochemical Solar Fuel Production
摘要： Transition metal chalcogenides are a promising family of materials for applications as photocathodes in photoelectrochemical (PEC) H2 generation. A long-standing challenge for chalcopyrite semiconductors is characterizing their electronic structure—both experimentally and theoretically—due to their relatively high energy bandgaps and spin orbit coupling (SOC), respectively. In this work, we present single crystals of CuInTe2, whose relatively small optically measured bandgap of 0.9 ± 0.03 eV enables electronic structure characterization by angle-resolved photoelectron spectroscopy (ARPES) in conjunction with first-principle calculations incorporating SOC. ARPES measurements reveal bands that are steeply dispersed in energy with a band velocity of 2.5-5.4 x 105 m/s, almost 50% of the extremely conductive material graphene. Additionally, CuInTe2 single crystals are fabricated into electrodes to experimentally determine the valence band edge energy and confirm the thermodynamic suitability of CuInTe2 for water redox chemistry. The electronic structure characterization and band edge position presented in this work provide kinetic and thermodynamic factors that support CuInTe2 as a strong candidate for water reduction.
关键词： photoelectrochemical H2 generation,electronic structure,spin orbit coupling,chalcopyrite semiconductors,band velocity,valence band edge energy,Transition metal chalcogenides,angle-resolved photoelectron spectroscopy,water redox chemistry,CuInTe2
更新于2025-09-10 09:29:36