Browsing by Author "Wei, Mao-Qugn"

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Efficiency Enhancement and Sensitive Broadband 1Hz similar to 1kHz of Power Generator by Recycling Vibration Energy on Automobile
(2012)
Wei, Mao-Qugn
;
Ko, Fu-Hsiang
;
Sun, Tai-Ping
;
Chen, Hsuen-Li
;
Lin, Yung-Bin
Based on novel design of moveable magnet between two mutually inimical magnetic forces without strict fabrication, for the first time, we demonstrate successfully a producible power generator with significant efficiency enhancement at broadband frequency range of 1 Hz similar to 1 kHz, 3D-colis stack-ability for output voltage improvement, and recycling vibration energy on automobile simultaneously. Even though the vibration frequency is as low as 1 Hz, two orders-of-magnitude improvements in normalized power (the ratio of power to product of external force and coil turns) provided from previous reports can be obtained. Further, comparing our device with maturely accelerometer chip (MMA7361) indicates that proposed strategies benefit harvesting vibration energy on driving automobile indeed. This vibrated power generator in-turn provides high potential for applications, such as human motion (1 Hz similar to 2 Hz), sporting (5 Hz similar to 10 Hz), and automotive (10 Hz similar to 1 kHz) etc..
High Optical Conversion Capability within the Interface between Graphene and Si under Zero Bias and Visible to Near Infrared Regime
(2016)
Hsiao, Chin-Chiang
;
Wei, Mao-Qugn
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Ren, Ting-Ting
;
Chen, Bo-Yi
;
Li, Mei-Yi
In this study, we demonstrate the high performance few-layer graphene-Si sensor with high photoresponsivity of 95 mA/W, operation behaviors with external bias as low as 0 V, and broadband operating light wavelength from 400 nm to 1000 nm by combining high transparency of few-layer graphene and n-type silicon. Although external bias benefits the photoresponsivity, the larger dark current is the price to pay. Under zero bias, the different Si substrate, n-type or p-type, provides variant Schottky barrier height guiding different photoelectrical behavior also be investigated in this work. According to the experimental results, few-layer graphene over p-type silicon (FLG p-Si) has one order higher the dark current of the few-layer graphene over n-type silicon (FLG n-Si) to ensure that the detection region between few-layer graphene and n-type silicon profits high optical-to-electrical conversion. Further, the capability of photocurrent-to-photovoltage conversion directly in one device is also provided and verified to profit the integration proposed device with periphery circuit easily.
High Photothermal Properties in Silicon Nanostructures
(2016)
Ren, Ting-Ting
;
Wei, Mao-Qugn
;
Hsiao, Chin-Chiang
;
Chen, Bo-Yi
;
Li, Mei-Yi
This research describes the p-type nanostalactites (p-type NS) with high photothermal conversion capability has been demonstrated by rapid INC process without extra heat treatment. In optical property, p-type NS has ultralow reflectance below 5 % and high light absorption due to rough structures in the broadband wavelength (350 nm -1100 nm). It looks like a black body. Silicon, an indirect band material, can release thermal energy during the recombination process of photo-generated electron-hole pairs. P-type NS converts photon energy into heat rapidly and then photothermal effect occurs. Then, the temperature change of p-type NS is faster in 10 second than bulk p-type silicon. These nanostructures can not only enhance thermal conversion efficiency but be regarded as a great heat absorber.