Browsing by Author "She, Nian-Zu"

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Crystalline Engineering Toward Large-Scale High-Efficiency Printable Cu(In,Ga)Se-2 Thin Film Solar Cells on Flexible Substrate by Femtosecond Laser Annealing Process
(2017-04-26)
Chen, Shih-Chen
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She, Nian-Zu
;
Wu, Kaung-Hsiung
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Chen, Yu-Ze
;
Lin, Wei-Sheng
Ink-printing method emerges as a viable way for manufacturing large-scale flexible Cu(In,Ga)Se-2 (CIGS) thin film photovoltaic (TFPV) devices owing to its potential for the rapid process, mass production, and low-cost nonvacuum device fabrication. Here, we brought the femtosecond laser annealing (fs-LA) process into the ink-printing CIGS thin film preparation. The effects of fs-LA treatment on the structural and optoelectronic properties of the ink-printing CIGS thin films were systematically investigated. It was observed that, while the film surface morphology remained essentially unchanged under superheating, the quality of crystallinity was significantly enhanced after the fs-LA treatment. Moreover, a better stoichiometric composition was achieved with an optimized laser scanning rate of the laser beam, presumably due to the much reduced indium segregation phenomena, which is believed to be beneficial in decreasing the defect states of In-se, V-Se, and In-cu. Consequently, the shunt leakage current and recombination centers were enhancement in photovoltaic conversion efficiency. both greatly decreased, resulting in a near 20%
Femtosecond Laser Crystallization for Boosting the Conversion Efficiency of Flexible Ink-Printing Cu(In,Ga)Se-2 Thin Film Solar Cells
(2017-01-01)
Chen, Shih-Chen
;
She, Nian-Zu
;
Juang, Jenh-Yih
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Chen, Yu-Ze
;
Kuo, Hao-Chung
We have successfully demonstrated that the femtosecond laser annealing treatment can give rise to significant improvements in both crystalline structure and defects reduction for the nonvacuum ink-printing CIGS thin films without introducing melting effect.
Improving Crystalline Quality of Non-Vacuum Processed Cu(In,Ga) Se-2 Thin Films by Femtosecond Laser Annealing
(2016)
Li, Jia-Xing
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She, Nian-Zu
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Chang, Yu-Hsuan
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Chen, Shih-Chen
;
Kuo, Hao-Chung
We demonstrate the advantages of femtosecond laser annealing on non-vacuum CIGS thin films. The PL spectra implied some defect-levels or band-fluctuations were eliminated, and the conversion efficiency and ideal factor were enhanced after laser annealing.
Realizing Efficient Charge/Energy Transfer and Charge Extraction in Fullerene-Free Organic Photovoltaics via a Versatile Third Component
(2019-08-01)
Cheng, Hao-Wen
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Zhang, Huotian
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Lin, Yu-Che
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She, Nian-Zu
;
Wang, Rui
Solution-processed organic photovoltaics (OPVs) based on bulk-heterojunctions have gained significant attention to alleviate the increasing demend of fossil fuel in the past two decades. OPVs combined of a wide bandgap polymer donor and a narrow bandgap nonfullerene acceptor show potential to achieve high performance. However, there are still two reasons to limit the OPVs performance. One, although this combination can expand from the ultraviolet to the near-infrared region, the overall external quantum efficiency of the device suffers low values. The other one is the low open-circuit voltage (V-OC) of devices resulting from the relatively downshifted lowest unoccupied molecular orbital (LUMO) of the narrow bandgap. Herein, the approach to select and incorporate a versatile third component into the active layer is reported. A third component with a bandgap larger than that of the acceptor, and absorption spectra and LUMO levels lying within that of the donor and acceptor, is demonstrated to be effective to conquer these issues. As a result, the power conversion efficiencies (PCEs) are enhanced by the elevated short-circuit current and V-OC; the champion PCEs are 11.1% and 13.1% for PTB7-Th:IEICO-4F based and PBDB-T:Y1 based solar cells, respectively.