Browsing by Author "Wang, Jen-Chun"

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Efficient inverted organic solar cells without an electron selective layer
(2011)
Wang, Jen-Chun
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Lu, Cheng-Yueh
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Hsu, Jui-Lin
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Lee, Ming-Kun
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Hong, Yun-Ru
Inverted organic solar cells which required no electron selective layer were fabricated and their power conversion efficiency was found to improve irreversibly from 1.46% to 4.10% with post-processing light soaking for 2 hours. X-Ray photoelectron spectroscopy characterization revealed further segregation in surface composition at the interface and was found to explain the current density-voltage measurements. In addition, the light soaked devices were found to exhibit extended lifetime as compared to conventional devices. Since no electron selective layer was required, light soaking may be considered as a cost-effective method to achieve efficient inverted organic solar cells.
Enhanced carrier extraction efficiency in organic solar cells with reduced space-charge limited transport by engineered vertical compositional profile
(2012-12-01)
Lee, Ming-Kun
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Kuo, Tsung-Han
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Kong, Kuo-Wen
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Hong, Yun-Ru
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Wang, Jen-Chun
A multi-layered polymer solar cell (PSC) with a graded compositional profile to reduce space-charge limited (SCL) transport was designed and analyzed in details. We found that by increasing the effective carrier lifetime for the slower photo-carriers. SCL effects that degrade the fill factor and the power conversion efficiency can be alleviated in PSCs with a thick active layer. The reduction of SCL effects was evidenced by a diminished dependence of the incident photon-to-electron conversion efficiency (IPCE) on light bias, which also indicates the importance of light bias in characterizing the operating IPCE of PSCs with thick active layers which operate in SCL region. Based on our results, device architecture to enhance FF was proposed. (C) 2012 Elsevier B.V. All rights reserved.
Extraction of solar cell series resistance without presumed current-voltage functional form
(2010-03-01)
Lee, Ming-Kun
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Wang, Jen-Chun
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Horng, Sheng-Fu
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Meng, Hsin-Fei
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物理研究所
A new method which does not require presumed current-voltage functional form is proposed for the determination of the series resistance, the shunt resistance, the photocurrent, and the intrinsic current-voltage characteristics of solar cells. This method was applied to analyze a bulk heterojunction organic solar cell. It was found that the extracted intrinsic current-voltage characteristic clearly exhibits a linear hopping current component and a quadratic space-charge limited current component. Furthermore, the reconstructed dark current-voltage curve is found to differ significantly from the measured dark current-voltage curve, revealing the importance of electric field in the operation of bulk heterojunction organic solar cells. (C) 2009 Elsevier B.V. All rights reserved.
Highly efficient flexible inverted organic solar cells using atomic layer deposited ZnO as electron selective layer
(2010-02-07)
Wang, Jen-Chun
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Weng, Wei-Tse
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Tsai, Meng-Yen
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Lee, Ming-Kun
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Horng, Sheng-Fu
Simultaneous enhancement in both large-area coatability and photovoltaic performance of inverted organic solar cells with co-solvent
(2014-01-01)
Hong, Yun-Ru
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Chen, Pin-Kuan
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Wang, Jen-Chun
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Lee, Ming-Kun
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Horng, Sheng-Fu
We report our observation of simultaneous enhancement in large-area coatability and photovoltaic performance for blade-coated inverted P3HT:PCBM organic solar cells with DCB:hexane co-solvent. The addition of hexane improves greatly the wettability of P3HT:PCBM blend layer on Cs2CO3 treated ITO and leads to excessively higher P3HT surface concentration due to the incongruent evaporation of hexane and DCB. A post-processing light soaking was found to further improve the photovoltaic performance for blade-coated devices prepared with co-solvent by adjusting the P3HT surface concentration ratio for more favorable carrier transport, as evidenced by the disappearance of current suppression at forward bias and significant increase in V-oc after light soaking. Since large-area manufacturing is the key to full commercialization of organic solar cells, the use of co-solvent, combined with light soaking, may be crucial for the development of inverted organic solar cells. (C) 2013 Elsevier B.V. All rights reserved.
Ultrathin Glass Wafer Lamination and Laser Debonding to Enable Glass Interposer Fabrication
(2015)
Shen, Wen-Wei
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Chang, Hsiang-Hung
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Wang, Jen-Chun
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Ko, Cheng-Ta
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Tsai, Leon
Interposer fabrication processes are applied in three-dimensional (3-D) integrated circuit (IC) integration to shorten the interconnection among different stacked chips and substrates. Because Si is a common material in semiconductor technology, Si interposers have been widely studied in many research activities. Compared with a Si wafer, glass substrates have the advantages of high resistivity, low dielectric constant, low insertion loss, adjustable coefficient of thermal expansion (CTE), and the possibility to use panel-size substrates as well as thin glass substrates (100 mu m) to avoid the costly thinning process for realization of low-cost 2.5-D ICs. Thus, glass interposer fabrication is studied thoroughly in this paper. Thin glass wafers have reduced mechanical stiffness. Therefore, handling and shipping thin glass wafers (<= 100 mu m) throughout the semiconductor fabrication and packaging assembly processes are critical. Temporary wafer bonding technology is used in this study to bond a thin glass wafer to a carrier to improve the rigidity. Vacuum lamination technology is used in this study as a bonding process to enhance the cost-effectiveness. After processing, the carrier is removed by laser debonding. The thin glass wafer with structures on both sides does not need to undergo a glass thinning process and saves a lot of cost compared to the traditional glass or Si interposer processes. Thin 300-mm glass wafers 100 mu m thick are evaluated as: (a) blank thin glass wafers and (b) thin glass wafers with through-glass vias (TGVs) 30 mu m in diameter. A UV laser with a wavelength of 308 nm, which has the benefit of less impact to the device, was adopted to laser debonding. This method also has several benefits such as high throughput, low temperature, zero-force debonding, and possible selective laser debonding. Adhesive and release layers are key enabling materials for thin glass handling. In addition, the use of a laminator for temporary bonding and laser debonding are included in this study. Based on the excellent fabrication, the thin glass interposer has great potential to be applied in 2.5-D integration applications.