Browsing by Author "Tsai, Yu Sheng"

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Adjusting optical resonance thickness to increase the conversion efficiency of polymer solar cells
(2010-05-01)
Tsai, Yu Sheng
;
Lin, Jian-Shian
;
Chu, Wei-Ping
;
Wang, Po-Hsun
;
Juang, Fuh-Shyang
The derivatives of C(60), [6,6]-phenyl C61-butyric acid methyl ester (PCBM), and 3-hexylthiophene (P3HT) were dissolved in DCB solvent, then spin coated into an active layer for polymer solar cells. The experimental parameters were studied carefully to obtain the optimum power conversion efficiency (PCE). The primary process for generation of photocurrent in an organic photovoltaic device is the generation of bound electron-hole pairs (excitons) by absorption of energy (photons) from the optical electric field. Modeling was based on the assumption that the photocurrent generation process is the result of the creation and diffusion of photogenerated species (excitons), which are dissociated by charge transfer at the active layer. Improve organic optics absorb by insert organic layer (CuPc or C60) at the active layer/Al interface. This research is divided into two components. First part, we use n-type C60 as transmission layer. When an optimum thickness of C(60) is 5 nm, the J(sc) of polymer solar cell can be increased from 7.26 mA/cm(2) to 7.7 mA/cm(2). The V(oc) decrease is because the energy level of C60 LUMO (lowest unoccupied molecular orbital) at 4.5 eV is higher than the 3.7 eV of PCBM. Second part, we use p-type CuPc as transmission layer. When an optimum thickness of CuPc is 3 nm, the short circuit photo-current density (J(sc)) and open circuit voltage (Voc) of polymer solar cell can be increased from 7.26 mA/cm2 to 8.0 mA/cm2 and 0.56-0.58 V, respectively. The reason is the same as C(60). The Voc increase is because the energy level of CuPc LUMO (lowest unoccupied molecular orbital) at 3.1 eV is lower than the 3.7 eV of PCBM. The Jsc increase is because the 3 nm of CuPc leads to a constructive interference happened in the active layer and thus optical absorption increases. In this study we used 3 nm of CuPc at the active layer/Al interface to enhance the short circuit current density, and the efficiency was increased to 2.94%. (C) 2010 Elsevier B. V. All rights reserved.
Comparison of Different Encapsulating Adhesives to Enhance the Efficiencies and Lifetimes of Polymeric Solar Cells
(2009-04-01)
Chung, Ming-Hua
;
Chen, Chen-Ming
;
Hsieh, Tsung-Eong
;
Tang, Rong-Ming
;
Tsai, Yu Sheng
Polymeric solar cells (PSCs) with a derivative of C(60) [[6,6]-phenyl C(61)-butyric acid methyl ester (PCBM)], and 3-hexylthiophene (P3HT) as active layers have been fabricated. The PSC devices were also packaged with glass and novel UV glues to improve their lifetimes and power conversion efficiencies (PCEs). After encapsulation with UV glue I, II, and III, the PCEs of PSCs reached 4, 4.82, and 6%, respectively, and their half-lifetimes increased to 16-18, 26-28, and 90 h, respectively, while the PCEs and half-lifetimes of PSCs without encapsulation were 3.76% and 2.5 h, respectively. (C) 2009 The Japan Society of Applied Physics
Morphological, Material, and Optical Properties of ZnO/ZnS/CNTs Nanocomposites on SiO(2)Substrate
(2020-08-01)
Tsai, Yu Sheng
;
Lin, Xin Dai
;
Chan, Wei Lun
;
Tsai, Shang Che
;
Liao, Wei Jen
Ultraviolet A light (UV-A, 320-400 nm), which is unblockable by sunscreen, requires careful detection for disease avoidance. In this study, we propose a novel photosensing device capable of detecting UV-A. Cancer-causing UV light can be simultaneously monitored with tiny rapid response sensors for a high carrier transition speed. In our research, a multifunctional ZnO/ZnS nanomaterial hybrid-sprinkled carbon nanotube (CNT) was created for the purpose of fabricating a multipurpose, semiconductorbased application. For our research, ZnO nanorods (NRs) were grown by using a facile hydrothermal method on SiO(2)substrate, then vulcanized to form ZnO/ZnS coreshell nanorods, which were sprinkled with carbon nanotubes (CNTs). Results indicate that SiO2/ZnO/ZnS/CNT structures exhibited a stronger conducting current with and without light than those samples without CNTs. Multiple material characterizations of the nanostructures, including of atomic force microscopy (AFM) surface morphology evaluation, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) indicate that CNTs could be successfully spread on top of the ZnO/ZnS coreshell structures. Furthermore, chemical binding properties, material crystallinity, and optical properties were examined by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and photoluminescence (PL). Owing to their compact size, simple fabrication, and low cost, ZnO/ZnS coreshell NRs/CNT/SiO2-based nanocomposites are promising for future industrial optoelectronic applications.
Using Mixed Solvent and Changing Spin-Coating Parameters to Increase the Efficiency and Lifetime of Organic Solar Cells
(2008-10-01)
Tsai, Yu Sheng
;
Chu, Wei-Ping
;
Tang, Rong-Ming
;
Juang, Fuh-Shyang
;
Chang, Ming-Hua
The derivative of C(60), i.e., PCBM, and P3HT (3-hexylthiophene) were dissolved in chloroform: dichlorobenzene mixed solvent, then spin-coated as the active layer for organic solar cells (OSC). The experimental parameters were studied carefully to obtain the optimum power conversion efficiency (PCE), including the solvent mixing ratio, spin-coating speed, annealing conditions for the active layer, etc. The OSC devices were packaged with glass and a newly developed UV-glue to improve the lifetime and PCE. Dichlorobenzene solvent has great effect upon the PCE. Changing the spin-coating speed and increasing the number of steps increased the PCE apparently to 1.4%.