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收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作,涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

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Now showing 1 - 9 of 9
  • Item type:Item,
    The Luminescent Down Shifting Effect of Single-Junction GaAs Solar Cell with Perovskite Quantum Dots
    (2019-01-01)
    Cho, Yu-Yun
    ;
    Huang, Yu -Ming
    ;
    Hsu, Shun-Chieh
    ;
    Kao, Sheng-Feng
    ;
    Shih, Hsiang-Yun
    In this work, we demonstrate the Luminescent Down Shifting (LDS) effect of the single-junction GaAs solar cell with 514 nm Perovskite quantum dots with and without bake treatment. One of results shows that Jsc from 22.22 mA/cm(2) to 23.38 mA/cm(2) and the efficiency from 17.70% to 18.96% as high as 5.22% and 7.12% enhancement. The enhancement includes antireflection and LDS effect, via our calculated the increase J. from LDS effect was 31.65% Further storage lifetime test shows great reliability from these devices can be expected.
  • Item type:Item,
    Feasibility Study for Double Luminescent Down-shifting Effect in A Dual Junction Solar Cell
    (2019-01-01)
    Huang, Yu-Ming
    ;
    Cho, Yu-Yun
    ;
    Hsu, Shun-Chieh
    ;
    Kao, Sheng-Feng
    ;
    Shih, Hsiang-Yun
    In this work, we discuss the feasibility of two color photons for boosting up the short-circuit current and power conversion efficiency in tandem solar cell. One of them is by luminescent down-shifting (LDS) effect, and the other one is the infrared light emitting diode at 820nm. The CdZnSeS/ZnS quantum dots are used in this study. It can convert ultra-violet photons to visible ones which could be efficiently transformed into electron-hole pairs. The infrared-radiation LED can increase photo-generated carriers of the bottom GaAs solar cell. Finally, short-circuit current would significantly increase from 10.46 mA/cm(2) to 13.81 mA/cm(2), and power conversion efficiency increase from 19.89 to 25.22%. This result shows the possible double-LDS effect for solar cell enhancement in the future.
  • Item type:Item,
    Evaluation of Luminescent Downshifting Effect of Perovskite Quantum Dots on Semiconductor Solar Cells
    (2018-01-01)
    Chen, Chun-Hong
    ;
    Yu, Chung-Ping
    ;
    Huang, Yu-Ming
    ;
    Chan, Yueh-Lin
    ;
    Huang, Chung-Ping
    The luminescent down-shifting effect of the perovskite quantum dots on single junction GaAs solar cells are examined and discussed. The perovskite quantum dots can provide an effective way to convert ultra-violet photons in solar spectrum to visible ones which can be transformed into electron-hole pairs more efficiently. Three different designs are tried: direct-dispense, ITO nano-whisker up and ITO nano-whisker down. In this experiment, we use perovskite quantum dots(QDs) with the concentration of 1mg/ml and emit photons of the wavelength 530nm (CsPbBr3), and the various volume of perovskite QDs were deposited on the solar cell to observe the possible luminescent down-shifting phenomenon.
  • Item type:Item,
    Liquid Type Nontoxic Photoluminescent Nanomaterials for High Color Quality White-Light-Emitting Diode
    (2018-12-22)
    Lin, Chih-Hao
    ;
    Pai, Yung-Min
    ;
    Lee, Chun-Fu
    ;
    Verma, Akta
    ;
    Lin, Huang-Yu
    High-brightness white-light-emitting diodes (w-LEDs) with excellent color quality is demonstrated by using nontoxic nanomaterials. Previously, we have reported the high color quality w-LEDs with heavy-metal phosphor and quantum dots (QDs), which may cause environmental hazards. In the present work, liquid-type white LEDs composed of nontoxic materials, named as graphene and porous silicon quantum dots are fabricated with a high color rendering index (CRI) value gain up to 95. The liquid-typed device structure possesses minimized surface temperature and 25% higher value of luminous efficiency as compare to dispensing-typed structure. Further, the as-prepared device is environment friendly and attributed to low toxicity. The low toxicity and high R9 (87) component values were conjectured to produce new or improve current methods toward bioimaging application.
  • Item type:Item,
    Colloidal Quantum Dot Enhanced Dual-Junction Tandem Solar Cells
    (2016-01-01)
    Hsu, Shun-Chieh
    ;
    Kao, Yu-Cheng
    ;
    Han, Hau-Vei
    ;
    Kuo, Hao-Chung
    ;
    Horng, Ray-Hua
    In this work, we demonstrate the the enhancement of two type hybrid QD dual-junction solar cell. The green QD520 sample, shows better performance than blue QD450 sample in current density and power conversion efficiency. The enhancement of short-circuit current and power conversion efficiency for green QD450 sample are 4.43% and 3.77% and the blue QD520 samples are 9.44% and 5.78%. For short wavelength, the enhancement can mainly be attributed to the photon downshift effect and antireflection, for long wavelength, it only the antireflection effect.
  • Item type:Item,
    High-quality Quantum-Dot-Based Full-Color Display Technology by Pulsed Spray Method
    (2013)
    Chen, Kuo-Ju
    ;
    Chen, Hsin-Chu
    ;
    Tsai, Kai-An
    ;
    Lin, Chien-Chung
    ;
    Tsai, Hsin-Han
    We fabricated the colloidal quantum-dot light-emitting diodes (QDLEDs) with the HfO2/SiO2-distributed Bragg reflector (DBR) structure using a pulsed spray coating method. Moreover, pixelated RGB arrays, 2-in. wafer-scale white light emission, and an integrated small footprint white light device were demonstrated. The experimental results showed that the intensity of red, blue, and green (RGB) emissions exhibited considerable enhancement because of the high reflectivity in the UV region by the DBR structure, which subsequently increased the use in the UV optical pumping of RGB QDs. In this experiment, a pulsed spray coating method was crucial in providing uniform RGB layers, and the polydimethylsiloxane (PDMS) film was used as the interface layer between each RGB color to avoid cross-contamination and self-assembly of QDs. Furthermore, the chromaticity coordinates of QDLEDs with the DBR structure remained constant under various pumping powers in the large area sample, whereas a larger shift toward high color temperatures was observed in the integrated device. The resulting color gamut of the proposed QDLEDs covered an area 1.2 times larger than that of the NTSC standard, which is favorable for the next generation of high-quality display technology.
  • Item type:Item,
    Improving efficiency of InGaN/GaN multiple quantum well solar cells using CdS quantum dots and distributed Bragg reflectors
    (2013-10-01)
    Tsai, Yu-Lin
    ;
    Lin, Chien-Chung
    ;
    Han, Hau-Vei
    ;
    Chang, Chun-Kai
    ;
    Chen, Hsin-Chu
    This work demonstrates hybrid InGaN/GaN multiple quantum well (MQW) solar cells with enhanced power conversion efficiency using colloidal CdS quantum dots (QDs) and back-side distributed Bragg reflectors (DBRs). CdS QDs can absorb ultraviolet (UV) photons, which are strongly absorbed by indium tin oxide (ITO), and they emit photons with a longer wavelength. This process improves the collection of photon-generated carriers and is known as the luminescence down-shifting (LDS). Accordingly, CdS QDs can compensate for the poor utilization of UV photons in an ITO layer, enhancing the external quantum efficiency (EQE) in the UV range. The DBRs on the back of the solar cells can reflect photons of longer wavelengths back into the absorber layer, increasing the EQE (380-440 nm). The combination of CdS QDs and DBRs results in broadband EQE enhancement, and yields an overall power conversion efficiency that is 20.7% better than that of a reference device without CdS QDs and DBRs. (C) 2013 Elsevier B.V. All rights reserved.
  • Item type:Item,
    Enhancement of power conversion efficiency in GaAs solar cells with dual-layer quantum dots using flexible PDMS film
    (2012-09-01)
    Chen, Hsin-Chu
    ;
    Lin, Chien-Chung
    ;
    Han, Hau-Vei
    ;
    Chen, Kuo-Ju
    ;
    Tsai, Yu-Lin
    "This study demonstrates the high performance of GaAs solar cells with dual-layer CdS quantum dots (QDs) carried by flexible polydimethylsiloxane (PDMS) film. Several parameters were enhanced, including the short circuit current, fill factor, and power conversion efficiency, which were measured under white light illumination similar to the solar spectrum. The flexible PDMS film was fabricated using the spin-coating technique, and was then used to embed dual-layer CdS QDs. Different concentrations of QDs were applied in this design to test the optimal combination. The proposed scheme enhances power conversion efficiency by 22%, compared to a GaAs solar cell without CdS QDs. The photon down-conversion capability in the ultraviolet (UV) range and additional antireflection capability in the longer visible-IR range were verified through the external quantum efficiency. (C) 2012 Elsevier B.V. All rights reserved."
  • Item type:Item,
    Improved efficiency for nanopillar array of c-Si photovoltaic by down-conversion and anti-reflection of quantum dots
    (2012)
    Lin, Chien-Chung
    ;
    Chen, Hsin-Chu
    ;
    Han, Hau-Vei
    ;
    Tsai, Yu-Lin
    ;
    Chang, Chia-Hua
    Improvement of efficiency for crystalline silicon (c-Si) with nanopillar arrays (NPAs) solar cell was demonstrated by deployment of CdS quantum dots (QDs). The NPAs was fabricated by colloidal lithography of self-assembled polystyrene (PS) nanospheres with a 600 nm in size and reactive-ion etching techniques, and then a colloidal CdS QDs with a concentration of 5 mg/mL was spun on the surface of c-Si with NPAs solar cell. Under a simulated one-sun condition, the device with CdS QDs shows a 33% improvement of power conversion efficiency, compared with the one without QDs. Additionally, we also found that the device with CdS QDs shows a 32% reduction in electrical resistance, compared with the one without QDs solar cell, under an ultraviolet (UV) light of 355nm illumination. This reduced electrical resistance can directly contribute to our fill-factor (FF) enhancement. For further investigation, the excitation spectrum of photoluminescence (PL), absorbance spectrum, current-voltage (I-V) characteristics, reflectance and external quantum efficiency (EQE) of the device were measured and analyzed. Based on the spectral response and optical measurement, we believe that CdS QDs not only have the capability for photon down-conversion in ultraviolet region, but also provide extra antireflection capability.