Browsing by Author "Chang, F. Y."

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Biomimetic Antireflection Coating for Efficiency Enhancement of Triple-Junction Solar Cells Utilizing Nanosphere Lithography
(2010)
Chiu, M. Y.
;
Chang, F. Y.
;
Chang, C. H.
;
Tsai, M. A.
;
Yu, Peichen
In this work, we demonstrate a thorough device design, fabrication, characterization, and analysis of biomimetic antireflective structures implemented on a Ga(0.5)In(0.5)P/GaAs/Ge triple-junction solar cell. The sub-wavelength structures are fabricated on a silicon nitride passivation layer using polystyrene nanosphere lithography followed by anisotropic etching. Both the reflectance spectroscopy and external quantum efficiency measurements confirm the improved optical absorption in the ultraviolet/blue and near-infrared wavelengths. Hence, the conversion efficiency of cell with sub-wavelength structure (SWS) is enhanced by 46.1% and 3.4% due to much improved current-matching, compare to cells without an ARC and SL ARC, respectively. We further employ RCWA method to analyze the reflectance by tuning structural factors such as periodicity or height of the SWS.
FLASH-TW experiment status report
(2005)
Liu, T. C.
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Chang, F. Y.
;
Chen, C. C.
;
Chen, C. W.
;
Huang, M. A.
FLASH-TW is an experiment to measure the shower lateral and longitudinal profiles. We perform the shower profile measurement by shooting the 1.5 GeV electron beams in NSRRC on targets made of 15 aluminum blocks, each with a thickness of 2.9 cm. A scintillator (Al2O3: Cr)) is placed behind the targets, converting the secondary shower particles into light. The light from the central region of the shower is recorded by a CCD camera while the light from the outer region is monitored by PMTs. The CCD system is successfully implemented in the run 2 and run 3 of experiment FLASH at SLAC. A test run of the current experiment has been conducted in NSRRC in the past June to study the scintillator spectrum. Two more runs are planned from now to the year 2006 to measure the shower lateral and longitudinal profiles.