學術出版;;Publications

Permanent URI for this communityhdl:11536/1

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.

Browse

🏛️國立陽明交通大學機構典藏

Search Results

Now showing 1 - 10 of 29

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.
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.
Coordinated and Simultaneous Formation of Paired Ge Quantum Dots by Thermal Oxidation of Designer Poly-SiGe Spacer Structures
(2020-01-01)
Chen, Han-Yu
;
Peng, Kang-Ping
;
George, Thomas
;
Lin, Horng-Chih
;
Li, Pei-Wen
We report a novel self-organized approach for the controllable placement of paired Ge quantum dots (QDs) along each sidewall edge of poly-Si ridges by simply thermally oxidizing spacer layers of poly-SiGe and Si3N4 that conformally encapsulate the poly-Si ridges. Additionally, controllable diameters ranging from 20-50 nm and precise location of paired Ge QDs are enabled by adjusting the thickness of poly-SiGe spacer layers in combination with specific processing conditions. These conditions include the subsequent lithographic patterning through direct etch-back for forming spacer stripes and spacer islands. The spacing between paired Ge QDs across the ridge is essentially determined by the width of the patterned poly-Si ridge. Inter-QD spacings along the sidewall of the poly-Si ridge are a consequence of heterogeneous nucleation and Ostwald Ripening.
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.
Continuous-Wave Lasing of 1.3-mu m Quantum-Dot Photonic-Crystal Surface-Emitting Lasers
(2018-01-01)
Hsu, Ming-Yang
;
Lin, Gray
;
Pan, Po-Chou
;
Chen, Yu-Chen
;
電子工程學系及電子研究所
Fabrication of electrically injected quantum-dot photonic-crystal (PC) surface-emitting lasers (SELs) is simplified by deposition of indium-tin-oxide over "PC slab-on-substrate" structure. Temperature-insensitive threshold current behavior is exhibited for negatively detuned PCSEL where continuous-wave lasing emission at 1308.4 nm is demonstrated for the first time.
Tailoring of the Wave Function Overlaps InAs/GaAs1-xSbx Type-II Quantum Dots
(2010-09-01)
Hsu, Wei-Ting
;
Liao, Yu-An
;
Lu, Shu-Kai
;
Cheng, Shun-Jen
;
Chiu, Pei-Chin
Effects of thermal annealing on the emission properties of type-II InAs quantum dots (QDs) covered by a thin GaAs1-xSbx layer are investigated by photoluminescence (PL) and time-resolved PL measurements. Apart from large blueshifts and a pronounced narrowing of the QD emission peak, the annealing induced alloy intermixing also leads to enhanced radiative recombination rates and reduced localized states in the GaAs1-xSbx layer. We find that the type-II QD structure can sustain thermal annealing up, to 850 degrees C. In particular, we find that it is possible to manipulate between type-I and type-II recombinations in annealed QDs by using different excitation powers. We demonstrate that postgrowth thermal annealing can be used to tailor the band alignment, the wave function overlaps, and hence the recombination dynamics in the InAs/GaAs1-xSbx type-II QDs. (C) 2009 Elsevier B.V. All rights reserved.
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.
A pyrophosphatase biosensor with photocurrent analysis
(2019-04-01)
Lee, Cheng-Yu
;
Liao, Chi-Hsiang
;
Tso, Jen-Te
;
Hsieh, You-Zung
;
交大名義發表
A light-induced photochemical biosensor was developed for the analysis of inorganic pyrophosphatase (PPase). PPase hydrolyzes pyrophosphate (PPi) into two independent o-phosphate ions. Two PPi units can chelate a copper ion (Cu2+), forming a PPi-Cu2+-PPi complex and preventing the Cu2+ triggers other reactions. A transparent indium tin oxide (ITO) electrode was coated with a layer of CdS quantum dots (QDs), and then 3,4-diaminobenzoic acid (DBA) was deposited as the anchor. A solution of the PPi-Cu2+-PPi complex and o-phenylenediamine (OPD) was mixed with the analytical sample and then a drop of the mixture was placed on the modified ITO electrode. In the absence of PPase, no reaction occurred between OPD and DBA. A photocurrent was obtained upon excitation of the CdS QDs under light. In the presence of PPase, Cu2+ was released from the complex, triggering the reaction of OPD with DBA on the electrode surface, thereby shielding the CdS QDs from excitation by the light. The observed photocurrent decreased. The difference in the two measured photocurrents corresponded to the activity of PPase. This photochemical biosensor had excellent sensitivity for PPase in the range from 0.8 to 5000 mU, with a limit of detection of 0.41 mU.
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.
Study of extending carrier lifetime in ZnTe quantum dots coupled with ZnCdSe quantum well
(2018-03-01)
Fan, W. C.
;
Chou, W. C.
;
Lee, J. D.
;
Lee, Ling
;
Nguyen Dang Phu
We demonstrated the growth of a self-assembled type-II ZnTe/ZnSe quantum dot (QD) structure coupled with a type-I Zn0.88Cd0.12Se/ZnSe quantum well (QW) on the (001) GaAs substrate by molecular beam epitaxy (MBE). As the spacer thickness is less than 2 nm, the carrier lifetime increasing from 20 ns to nearly 200 ns was successfully achieved. By utilizing the time-resolved photoluminescence (TRPL) and PL with different excitation power, we identify the PL emission from the coupled QDs consisting of two recombination mechanisms. One is the recombination between electrons in ZnSe barrier and holes confined within ZnTe QDs, and the other is between electrons confined in Zn0.88Cd0.12Se QW and holes confined within ZnTe QDs. According to the band diagram and power-dependent PL, both of the two recombinations reveal the type-II transition. In addition, the second recombination mechanism dominates the whole carrier recombination as the spacer thickness is less than 2 nm. A significant extension of carrier lifetime by increasing the electron and hole separation is illustrated in a type-II ZnTe/ZnSe QD structure coupling with a type-I ZnCdSe/ZnSe QW. Current sample structure could be used to increase the quantum efficient of solar cell based on the II-VI compound semiconductors.

學術出版;;Publications

Browse

Filters

Settings

Sort By

Results per page

🏛️國立陽明交通大學機構典藏

Search Results