High-responsivity thermoelectric infrared detectors with stand-alone sub-micrometer polysilicon wires

    Authors

    M. J. Modarres-Zadeh;R. Abdolvand

    Comments

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    Abbreviated Journal Title

    J. Micromech. Microeng.

    Keywords

    thermoelectric; thermopile; infrared detector; polysilicon; low noise; high responsivity; POLYCRYSTALLINE SILICON FILMS; THERMAL-CONDUCTIVITY; OPTICAL-CONSTANTS; THIN-FILMS; TRANSMITTANCE; PERFORMANCE; REFLECTANCE; FIGURES; MERIT; Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Instruments & Instrumentation; Materials Science, Multidisciplinary; Mechanics

    Abstract

    A novel high-responsivity uncooled thermoelectric (TE) infrared (IR) detector is designed, fabricated and characterized. This detector features a single stand-alone polysilicon-based thermocouple (without a supporting membrane) covered by an umbrella-like optical cavity IR absorber. It is proved that the highest responsivity in the developed detectors can be achieved with only one thermocouple. Using a single thermocouple also results in a low resistance detector, which consequently limits the Johnson noise (e.g. less than 30 nv/root Hz in this work). Since the sub-micrometer polysilicon TE wires are the only heat path from the hot junction to the substrate, a superior thermal isolation is achieved. A responsivity of 1800 V W-1 and a detectivity of 2* 10(8) (cm Hz(1/2) W-1) are measured from a 20 x 20 mu m detector comparable to the performance of detectors used in commercial focal planar arrays [1]. This performance in a compact and manufacturable design elevates the position of thermoelectric IR sensors as a candidate for low-power, high performance and inexpensive focal planar arrays.

    Journal Title

    Journal of Micromechanics and Microengineering

    Volume

    24

    Issue/Number

    12

    Publication Date

    1-1-2014

    Document Type

    Article

    Language

    English

    First Page

    9

    WOS Identifier

    WOS:000345824400013

    ISSN

    0960-1317

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