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- 实验方案
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Performance, Limits, and Thermal Stress Analysis of High Concentrator Multijunction Solar Cell under Passive Cooling Conditions
摘要： Concentration of solar radiation onto the surface of triple-junction solar cells causes high cell temperature and system failure. Recently, several cooling methods were proposed for these systems. However, quantitative evaluation of the essential heat transfer coefficients to maintain stable operation of these systems at different meteorological and operating conditions is not found in the literature. Therefore, in this study, a comprehensive three-dimensional coupled thermal and structural model is proposed for the latest triple-junction AZUR SPACE solar cell. The model is used to investigate the performance of an HCPV system under different solar concentration ratios (CRs), ambient temperature, direct solar irradiance, wind speed, backside heat transfer coefficient, and copper-II substrate area ratios. In addition, a new structure of the solar cell is proposed by modifying the typical solar cell assembly by changing the area of the rear copper layer. The results indicate that by increasing the ambient temperature, CR and direct solar irradiance significantly increase the predicted cell temperature at the same backside heat transfer coefficient. In addition, increasing copper-II substrate area ratios significantly reduces the average cell temperature at the same backside heat transfer coefficient and CR. At the highest backside heat transfer coefficient, when the copper-II substrate area increased, the cell temperature decreased to a certain limit and subsequently remained constant. Critical values of the highest backside heat transfer coefficient were about 200, 600, 1000, and 1600 W/m2 K at CRs of 50, 500, 1000, and 1500 Suns, respectively. In addition, at the highest backside heat transfer coefficient of 1600 W/m2 K, the critical area ratio values were about 2, 3, 4, and 6 at CRs of 50, 500, 1000, and 1500 Suns, respectively.
关键词： Passive cooling,Concentrator photovoltaic,Thermal stress,Triple-junction solar cell
更新于2025-09-16 10:30:52
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Physical properties of electrodeposited CIGS films on crystalline silicon: Application for photovoltaic heterojunction
摘要： P-type CIGS (CuIn1-xGaxSe2) thin films are electro-deposited on a p-type c-Si substrate with a galvanostatic mode to form CIGS(p)/c-Si(p) hetero-junction. The Ga content is varied up to x = 30%. The physical properties of formed CIGS films are characterized by XRD, SEM, EDS and UV-Visible spectroscopy. With x = 30%, we obtain a single chalcopyrite phase of CIGS with a tetragonal crystal structure, a high crystallinity, an orientation toward the (112) direction and a band gap energy of 1.40 eV. AM1.5 J-V performed on the CuI0.7G0.3Se2/c-Si hetero-junction reveals interesting photovoltaic parameters with an efficiency of 3.75%. In addition, using the energy diagram of the hetero-junction calculated with the Anderson model, we show that it could play a dual role when it is combined to a c-Si cell in a Ag-Al/c-Si(n+)/c-Si(p)/CIGS(p)/Al new architecture. Therefore, in addition to its interesting photovoltaic parameters, this hetero-junction can substitute the BSF.
关键词： Electro-deposition,Hetero-junction,CIGS,Silicon
更新于2025-09-16 10:30:52
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Optimization of back ITO layer as the sandwiched reflector for exploiting longer wavelength lights in thin and flexible (30?μm) single junction c-Si solar cells
摘要： Fabrication of thin and ?exible crystalline silicon solar cells based on single junction concept is reported with detailed investigations on each step of the production ?ow chain. With the aim of minimizing material use/wastage as per the international technology roadmap for photovoltaic (ITRPV), which is also directly related to the device cost, e?orts have been made to introduce thin (~30 μm) c-Si wafers instead of a conventional 180 μm wafer to fabricate single-junction solar cells. Due to the introduction of thin (~30 μm) c-Si wafer, the device becomes ?exible, which is also an additional bene?t towards the development of future roll-to-roll electronics. In order to address better carrier collection in thin silicon as well as light management, measures have been taken by introducing an indium tin oxide (ITO) layer both on top and at the bottom. The in?uence of this ITO layer along with back Al contact toward the cell e?ciency has been discussed. X-ray di?raction (XRD) analysis has been carried out to investigate microstrain and dislocation density related changes in the thin wafer, which are known to have in?uence on the photoconversion e?ciency. Under 1 Sun illumination, current – voltage characteristics and external quantum e?ciency were measured and found to be promising.
关键词： Sandwiched back ITO layer,Theoretical validation,Single junction,Thin silicon solar cells,Monocrystalline Si
更新于2025-09-16 10:30:52
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Vis–IR wide-spectrum photodetector at room temperature based on p-n junction-type GaAs1-xSbx/InAs core-shell nanowire
摘要： Infrared (IR) detection at room temperature is very important in many fields. Nanoscale wide-spectrum photodetectors covering IR range are still rare, although they are desired in many applications, such as in integrated optoelectronic devices. Here, we report a new kind of photodetector based on p?n heterojunction-type GaAs1-xSbx/InAs core-shell nanowires. The photodetectors demonstrate high response to the lights ranging from visible light (488 nm) to short-wavelength IR (1800 nm) at room temperature under a very low bias voltage of 0.3 V. The high performances of the devices include an ultralow dark current (32 pA at room temperature), a fast response speed (0.45 ms) to 633 nm light, high responsivity to 1310 nm telecommunication light (0.12 A/W), and high response even to 1800 nm light (on/off ratio of 2.5), etc. Besides, the devices also show excellent rectifying I-V characteristics (the current rectification ratio being ~178 in a voltage range of ± 0.3 V). These results suggest that the GaAs1-xSbx/InAs core-shell nanowires devices are promising for applications in nanoelectronic devices, optoelectronic devices and integrated optoelectronic devices.
关键词： P-N junction,IR,III-V nanowires,core-shell nanowires,Photodetector
更新于2025-09-16 10:30:52
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Ideal <i>pn</i> Diodes from Single-Walled Carbon Nanotubes for Use in Solar Cells: Beating the Detailed Balance Limit of Efficiency
摘要： Though many technologies exist for improving solar cell efficiencies, there remains an unexplored fundamental parameter, the diode ideality factor (??), that we can exploit. The Shockley-Queisser limit states that the maximum solar conversion efficiency in a single pn junction is achievable only when it is operated in the ideal diode limit of ?? = 1. Generation and recombination losses correlate directly to an increase in the dark saturation current and ??, both of which have competing effects on the open-circuit voltage. Here, we demonstrate a new approach to improving the efficiency of solar cells beyond the detailed balance limit by gate modulation of the diode’s ideality factor in ideal carbon nanotube pn diodes. We show that the open-circuit voltage can be tuned in direct proportion to ?? without impacting the reverse bias leakage current or the short circuit current. We show that our approach is similar to the enhancement from solar concentrators without actually using them. We achieve an open-circuit voltage that is ~300% higher than that given by the detailed balance limit.
关键词： pn junction,photovoltaic effect,open-circuit voltage,gate-tunable diodes,Single-walled carbon nanotube,detailed balance limit
更新于2025-09-16 10:30:52
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Electrostatically Doped Silicon Nanowire Arrays for Multispectral Photodetectors
摘要： Nanowires have promising applications as photodetectors with superior ability to tune absorption with morphology. Despite their high optical absorption, the quantum efficiencies of these nanowire photodetectors remain low due to difficulties in fabricating a shallow junction using traditional doping methods. As an alternative, we report non-conventional radial heterojunction photodiodes obtained by conformal coating of indium oxide layer on silicon nanowire arrays. The indium oxide layer has a high work function which induces a strong inversion in the silicon nanowire and creates a virtual p-n junction. The resulting nanowire photodetectors show efficient carrier separation and collection leading to an improvement of quantum efficiency up to 0.2. In addition, by controlling the nanowire radii, the spectral response of the In2O3/Si nanowire photodetectors are tuned over several visible light wavelengths, creating a multispectral detector. Our approach is promising for the development of highly-efficient wavelength selective photodetectors.
关键词： electrostatic doping,nanowire photodetectors,multispectral,photosensors,silicon nanowire,dopant-free,radial junction
更新于2025-09-16 10:30:52
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[IEEE 2019 XXIVth International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory (DIPED) - Lviv, Ukraine (2019.9.12-2019.9.14)] 2019 XXIVth International Seminar/Workshop on Direct and Inverse Problems of Electromagnetic and Acoustic Wave Theory (DIPED) - General Resonance Condition for Waveguide Junctions with Natural Dielectric Inserts
摘要： A general resonant condition for rectangular waveguide junctions operating in the single mode regime of the main waveguide is formulated based on previously developed mathematical models. We will consider three types of junction with various side arms: semi-infinite waveguide oriented in line with main waveguide, T-oriented semi-infinite waveguide with an impedance end wall, and infinite perpendicularly oriented waveguide. The main waveguide is coupling with the side arm through a narrow slot, and it has a dielectric insert in the coupling region. The simulation results obtained for the waveguide junctions have shown that the resonant conditions allow to attain correct results without taking into account the imaginary part of permittivity of the insert material.
关键词： Waveguide junction,narrow slot,rectangular waveguide,dielectric insert,resonant condition
更新于2025-09-16 10:30:52
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Hole-transporting materials for low donor content organic solar cells: Charge transport and device performance
摘要： Low donor content solar cells are an intriguing class of photovoltaic device about which there is still considerable discussion with respect to their mode of operation. We have synthesized a series of triphenylamine-based materials for use in low donor content devices with the electron accepting [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM). The triphenylamine-based materials absorb light in the near UV enabling the PC71BM to be essentially the light absorbing organic semiconducting material in the solar cell. It was found that the devices did not operate as classical Schottky junctions but rather photocurrent was generated by hole transfer from the photoexcited PC71BM to the triphenylamine-based donors. We found that replacing the methoxy surface groups with methyl groups on the donor material led to a decrease in hole mobility for the neat films, which was due to the methyl substituted materials having the propensity to aggregate. The thermodynamic drive to aggregate was advantageous for the performance of the low donor content (6 wt%) films. It was found that the 6 wt% donor devices generally gave higher performance than devices containing 50 wt% of the donor.
关键词： hole mobility,low donor content,photoexcited hole transfer,Schottky junction,synthesis,photocurrent generation
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 4th Optoelectronics Global Conference (OGC) - Shenzhen, China (2019.9.3-2019.9.6)] 2019 IEEE 4th Optoelectronics Global Conference (OGC) - The Comparative Study of Using Si and Te Doping Tunnel Junction of Vertical Hetero-structure Laser Photovoltaic Cell
摘要： Heavy doping of epitaxial tunnel junction layers is of interest in vertical hetero-structure laser photovoltaic cell the performance characteristic of AlGaAs/GaAs junctions with silicon(Si) and tellurium (Te) doped were presented, respectively. Compared to Si doping, the tunnel junction diode doped with Te doping revealed lower tunneling resistance and better performance. A comparative study using both Si and Te doping in the AlGaAs/GaAs tunnel junction of six junctions monochromatic laser photovoltaic cells also showed a higher photoelectric efficiency for Te doping. Therefore, the tunnel junction with Te doping can be considered to improve the performance of monochromatic laser cells.
关键词： si-doped,tunnel junction,te-doped,monochromatic laser cell,efficiency
更新于2025-09-16 10:30:52
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Investigation on Industrial Screen-Printed Aluminum Point Contact and Its Application in n-PERT Rear Junction Solar Cells
摘要： As compared with the traditional back surface field (BSF) solar cells, the n-type passivated emitter rear and totally diffused rear-junction (n-PERT-RJ) solar cells have much lower carrier recombination losses on their rear sides. In order to obtain more benefits (higher open-circuit voltages) from the currently passivated rear sides, the implementation of the point contact concept is an intuitive solution. In this article, we present industrial screen-printed point contacts that are metallized with aluminum (Al) pastes containing silicon additives (Si-add). To understand the impacts of the Si-add on the performance our n-PERT-RJ solar cells, the detailed loss analysis on the open-circuit voltage (VOC), short-circuit current density (JSC), and fill factor are performed separately. The effect of Si-add and pitch of laser contact openings (LCO) on the point contact characteristics are also investigated. In the last part, we introduce an innovative “point-line” contact concept on the rear side, which is composed of dot-shaped LCO and Al metal finger design, resulting in an n-PERT-RJ solar cell to reach VOC of 692 mV and peak efficiency of 22%. The 60% bifaciality of the device opens the way for an additional power output on module level, which further reduces the levelized cost of electricity. These features make the rear-side point contact design more flexible to be applied in industrial mass production.
关键词： laser contact opening (LCO),levelized cost of electricity,Aluminum (Al) paste,n-type passivated emitter rear and totally diffused (n-PERT),bifaciality,silicon solar cell,industrial,point contacts,screen printed,n-type,rear junction
更新于2025-09-16 10:30:52