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oe1(光电查) - 科学论文

316 条数据
?? 中文(中国)
  • Minimizing Defect States in Lead Halide Perovskite Solar Cell Materials

    摘要: In order to reach the theoretical e?ciency limits of lead-based metal halide perovskite solar cells, the voltage should be enhanced because it su?ers from non-radiative recombination. Perovskite materials contain intrinsic defects that can act as Shockley–Read–Hall recombination centers. Several experimental and computational studies have characterized such defect states within the band gap. We give a systematic overview of compositional engineering by distinguishing the di?erent defect-reducing mechanisms. Doping e?ects are divided into in?uences on: (1) crystallization; (2) lattice properties. Incorporation of dopant in?uences the lattice properties by: (a) lattice strain relaxation; (b) chemical bonding enhancement; (c) band gap tuning. The intrinsic lattice strain in undoped perovskite was shown to induce vacancy formation. The incorporation of smaller ions, such as Cl, F and Cd, increases the energy for vacancy formation. Zn doping is reported to induce strain relaxation but also to enhance the chemical bonding. The combination of computational studies using (DFT) calculations quantifying and qualifying the defect-reducing propensities of di?erent dopants with experimental studies is essential for a deeper understanding and unraveling insights, such as the dynamics of iodine vacancies and the photochemistry of the iodine interstitials, and can eventually lead to a more rational approach in the search for optimal photovoltaic materials.

    关键词: semiconductor,solar energy,photovoltaics,doping,thin ?lm materials,voltage loss,stabilization,optimization,charge generation,light harvesting

    更新于2025-09-23 15:21:01

  • Tandem photoelectrochemical cells for solar water splitting

    摘要: Photoelectrochemical (PEC) water splitting without an external bias is a potential solution to the growing energy crisis because this method can directly convert solar energy into chemical energy. A tandem cell is a frequently used configuration for unassisted overall water splitting because of the advantages that each component are tied together to form a highly efficient integration. A tandem PEC water splitting device is based on different photoelectrode absorbers, and there are two main models including photoanode/photocathode (PEC/PEC) and photoelectrode/photovoltaic (PEC/PV) tandem cells. In this review, we will focus on the concepts, configurations and recent progress of PEC/PEC and PEC/PV cells. Light absorption and energy band matching are the key points to enhance the solar-to-hydrogen (STH) efficiency. Promoting the performance of a standalone semiconductor material and finding new materials, coupled with an optimized configuration, are future steps for the practical application of tandem PEC cells.

    关键词: Solar energy,photoelectrochemical cell,tandem cell

    更新于2025-09-23 15:21:01

  • Highly Efficient Inorganic-Organic Heterojunction Solar Cells Based on Polymer and CdX (X=Se, Te) Quantum Dots: An Insight from a Theoretical Study

    摘要: By using the density functional method, we explore the potentiality of recently synthesized CdX (X=Se, Te)QD/P3HT composites in solar energy conversion devices. Our study reveals that inorganic/organic hybrid CdXQD/P3HT nanocomposites with larger size of CdX QDs exhibit type-II band alignment, suggesting efficient charge separation upon photoexcitation. But for smaller size of QDs, the composites show type-I band alignment which are devoid of charge separation and thus are not suitable for solar cell applications. To remove this obstacle, we focus on chemical modification to polymer P3HT. The substitution of hydrogen at the beta position of each thiophene ring of polymer by electron withdrawing group (CN) results type-II band alignment and yield spatial charge separation even for smaller size of QDs. Finally, we calculated the powerconversion efficiency (PCE) of CdXQD and CN functionalized P3HT nanocomposites. The maximum calculated PCE value of 10.82% is achieved, which makes them immensely competitive with other reported heterojunction solar cells.

    关键词: CdX (X=Se, Te)QD/P3HT composites,powerconversion efficiency,solar energy conversion,charge separation,type-II band alignment

    更新于2025-09-23 15:21:01

  • Influence of DC electric and magnetic fields on silicon solar cells/modules

    摘要: In this study, the impact of DC electric and magnetic fields on the output power, open-circuit voltage, and photocurrent density of a silicon photovoltaic (PV) cell/module is assessed. In this regard, the influence of DC electric and magnetic fields is first evaluated in theory by formulating and discussing related basis and concepts. Then, experimental measurements and data obtained from two different sets of experiments are given that verify theoretical results. In theory and practice, it is shown that depending on the direction of a DC electric field applied to a silicon PV cell/module, it causes an increase or reduction in the output power and open-circuit voltage of the PV cell/module. In detail, when the DC electric field points in the direction of the junction electric field of the PV cell(s), the output power and open-circuit voltage of the silicon PV cell/module increase, otherwise the output power and open-circuit voltage decrease. Regarding the magnetic field, it is proved that depending on the direction of a DC magnetic field applied to a silicon PV cell/module, different effects are observed. In detail, when the DC magnetic field points along the junction electric field of the PV cell(s), it has no effect on the output power and open-circuit voltage of the silicon PV cell/module. But, the output power and open-circuit voltage of the silicon PV cell/module decrease when the DC magnetic field points in the other directions. Moreover, the reduction in the output power and open-circuit voltage reaches its peak when the DC magnetic field is applied in the direction perpendicular to the junction electric field.

    关键词: DC electric field,solar energy,silicon PV cell,silicon PV module,DC magnetic field

    更新于2025-09-23 15:21:01

  • Novel parabolic trough solar collector and solar photovoltaic/thermal hybrid system for multi-generational systems

    摘要: A novel hybrid system, comprising a parabolic trough solar collector and solar photovoltaic/thermal collector units, is proposed and structured for useful multi-generational purposes with hydrogen production. The designed system comprises a parabolic trough solar collector for electricity generation, hydrogen production, and cooling applications. The solar photovoltaic/thermal collector modules serve the purposes of hydrogen production and space heating. A thermodynamic analysis was conducted for practical applications and implementation. The overall energy and exergy efficiencies of the system were calculated to be 12.90% and 54.72%, respectively, for a solar fluid exit temperature of 477 K. The hydrogen production could reach up to 8.226 g/s from the parabolic trough solar collector electrolyzer and 0.07518 g/s from the solar photovoltaic/thermal collector electrolyzer, which could be used for various useful domestic, medical, and industrial applications. The effects of varying the solar fluid exit temperature, incident solar irradiation, ambient temperature, and working fluids on the working system capability were examined. The proposed system demonstrated that the standalone solar hybrid system could serve as a vital tool for essential energy output purposes that are physically practical and economically viable.

    关键词: Heating,Solar energy,Power generation,Hydrogen production,Exergy,Efficiency,Cooling

    更新于2025-09-23 15:21:01

  • Experimental analysis of a photovoltaic/thermoelectric generator using cobalt oxide nanofluid and phase change material heat sink

    摘要: Nowadays, photovoltaic panels have been known as effective devices to harness solar energy. These panels mainly convert the UV and visible areas of the solar spectrum into electricity and the rest of the energy is dissipated. One of the favorable methods to take advantage of such dissipated heat is to combine thermoelectric generators (TEG) utilizing the IR area of the solar radiation with photovoltaic panels. Having the different and opposite impact on the efficiency of thermal photovoltaic cells (PV/T) and thermoelectric generators (TEG), the system operating temperature appears as a critical parameter in the productivity of a PV/T-TEG hybrid unit. In the present study, a novel heat sink for a PV/T-TEG hybrid system is introduced. The effectiveness of simultaneous usage of the Co3O4/water nanofluid and the improved phase change material (paraffin wax/Alumina powder) as a cooling method on the performance of the PV/T-TEG is examined throughout an experimental study. Then, the overall electrical, thermal and exergy efficiency of such a system is compared to the units with divers working fluids including water and 0.25%, 0.5%, and 1% nanofluid and the unit consisting of 1% nanofluid with non-enhanced PCM cooling method. The results reveal that using 1% nanofluid with enhanced PCM, as a cooling method, would improve the overall electrical efficiency by 12.28% compared to water cooling technique. Also, an increase of 11.6% in the exergy efficiency of the PV/T-TEG is observed in comparison with PV/T-TEG with the water cooling method. Hence, it could be concluded that the combination of this unit could contribute to harnessing solar energy more efficiently, compared to solo photovoltaic panels.

    关键词: Photovoltaic thermal,Solar energy,Nanofluid,Thermoelectric generator,Phase change material

    更新于2025-09-23 15:21:01

  • Data on combination of parabolic solar system with CH4 cycle and power tower solar system with Cu–Cl cycle for hydrogen production in the city of Ghardaia (Algeria)

    摘要: This data show the combination of parabolic through solar system with CH4 cycle and power tower solar system with Cu–Cl cycle for hydrogen production capacity in the city of Gharadaia which is located in the south of Algeria. A proper measurement of meteorological factors such as temperature, humidity, and solar irradiation has been done in the city of Ghardaia due to the solar concentration in this city. In the meantime thermo-chemical systems (Cu–Cl, CH4 cycles) have been integrated with the thermal solar systems through.

    关键词: Solar energy,Hydrogen production

    更新于2025-09-23 15:21:01

  • An environmentally conscious photovoltaic supply chain network design under correlated uncertainty: A case study in Iran

    摘要: As the destructive impacts of unbridled use of fossil fuels threaten the quality of life, moving towards renewable energy like solar power has precipitated. While such movements are commendable, environmental impacts of its infrastructure development should not be overlooked. In this sense, this paper addresses a multi-objective robust mathematical model to study an environmentally conscious solar photovoltaic supply chain under correlated uncertainty. The proposed model aims at minimizing the environmental impacts of included activities in the concerned supply chain in addition to minimizing the conventional cost objective. To quantify and assess the relevant environmental impacts, a life cycle assessment-based model is accomplished employing the ReCiPe 2008 approach embedded in the SimaPro software tool. The augmented ?-constraint procedure is deployed to optimize the proposed multi-objective model, which is able to attain compromise solutions from the Pareto-optimal set. Correlated uncertainty whose importance is underlined in the real-life situations of the photovoltaic industry is also tackled exploiting a robust optimization method. Ultimately, the validity of the presented model is vindicated through discussing a case study. The acquired results endorse the effectiveness and usefulness of the model and offer prominent practical and managerial insights.

    关键词: Environmental responsibility,Multi-objective optimization,Correlated uncertainty,Solar energy,Life cycle assessment,Photovoltaic supply chain

    更新于2025-09-23 15:21:01

  • Performance and stability enhancement of Cu(InGa)Se2 solar cells on ultrathin glass by potassium incorporation

    摘要: Flexible Cu(InGa)Se2 solar cells fabricated on metal foils and plastics have achieved high conversion efficiency so far. However, metal impurities and low temperature tolerance hinder them from further considerable development. Here, 150 lm-thick ultrathin glass with desirable advantages was applied as substrate for Cu(InGa)Se2 solar cell. Potassium element was doped by a simple method during the post-selenization process. The results showed that the KInSe2 phase existed in K-doped Cu(InGa)Se2 films. The K-doped CIGS films were more compact than the pristine one due to the fact that K incorporated in films could form quasi-liquid alkali-metal-Se compounds and improve the compactness of films. K-incorporated CIGS films exhibited enhanced p-type conductivity and different surface energy level. Consequently, K-doped Cu(InGa)Se2 solar cell achieved an optimal efficiency of 8.3%, which was relatively 43% higher than that of pristine solar cell. Investigation of performance and stability of solar cells manifested that the K incorporation retarded the performance degradation of device during cyclic bending.

    关键词: Potassium incorporation,Ultrathin glass,Cu(InGa)Se2,Thin films,Solar energy materials

    更新于2025-09-23 15:21:01

  • The electronic structures and optical properties of B, C or N doped BaTiO <sub/>3</sub>

    摘要: The electronic structures and optical properties of Boron, Carbon or Nitrogen doped BaTiO3 are calculated by the first-principles calculations. The doped atoms decrease the band gap of BaTiO3 significantly, which could increase the host material ability to absorb the visible light. The absorption spectrum calculations confirm that both Boron and Carbon-doped BaTiO3 have a favorable performance in the absorption of visible light. However, Nitrogen-doped BaTiO3 doesn’t present the improvement. BaTiO3 doped with Boron or Carbon is expected to be a new class of perovskite materials for the field of solar energy.

    关键词: BaTiO3,doping,optical properties,solar energy,electronic structures

    更新于2025-09-23 15:21:01