Current Search: Modarres-Zadeh, Mohammad (x)
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Title
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Uncooled Infrared Detector Featuring Silicon based Nanoscale Thermocouple.
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Creator
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Modarres-Zadeh, Mohammad, Abdolvand, Reza, Sundaram, Kalpathy, Yuan, Jiann-Shiun, Malocha, Donald, Cho, Hyoung Jin, University of Central Florida
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Abstract / Description
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The main focus of this dissertation is to improve the performance of thermoelectric (TE)infrared (IR) detectors. TE IR detectors are part of uncooled detectors that can operate at roomtemperature. These detectors have been around for many years, however, their performance hasbeen lower than their contesting technologies. A novel high-responsivity uncooled thermoelectricinfrared detector is designed, fabricated, and characterized. This detector features a single standalonepolysilicon-based...
Show moreThe main focus of this dissertation is to improve the performance of thermoelectric (TE)infrared (IR) detectors. TE IR detectors are part of uncooled detectors that can operate at roomtemperature. These detectors have been around for many years, however, their performance hasbeen lower than their contesting technologies. A novel high-responsivity uncooled thermoelectricinfrared detector is designed, fabricated, and characterized. This detector features a single standalonepolysilicon-based thermocouple (without a supporting membrane) covered by an umbrellalikeoptical-cavity IR absorber. It is proved that the highest responsivity in the developed detectorscan be achieved with only one thermocouple. Since the sub-micrometer polysilicon TE wires arethe only heat path from the hot junction to the substrate, a superior thermal isolation is achieved.A responsivity of 1800 V/W and a detectivity of 2 ? 10^8 (cm. sqrt(Hz)W^?1) are measured from a20?m x 20?m detector comparable to the performance of detectors used in commercial focalplanar arrays. This performance in a compact and manufacturable design elevates the position ofthermoelectric IR sensors as a candidate for low-power, high performance, and inexpensive focalplanar arrays. The improvement in performance is mostly due to low thermal conductivity of thinpolysilicon wires. A feature is designed and fabricated to characterize the thermal conductivity ofsuch a wire and it is shown for the first time that the thermal conductivity of thin polysilicon filmscan be much lower than that of the bulk. Thermal conductivity of ~110nm LPCVD polysilicondeposited at 620C is measured to be ~3.5W/m.K.
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Date Issued
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2016
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Identifier
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CFE0006537, ucf:51321
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Format
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Document (PDF)
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PURL
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http://purl.flvc.org/ucf/fd/CFE0006537
