Title

High-Responsivity Thermoelectric Infrared Detectors With Stand-Alone Sub-Micrometer Polysilicon Wires

Keywords

high responsivity; infrared detector; low noise; polysilicon; thermoelectric; thermopile

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/√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∗ 108 (cm Hz1/2 W-1) are measured from a 20 × 20 μm 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.

Publication Date

12-1-2014

Publication Title

Journal of Micromechanics and Microengineering

Volume

24

Issue

12

Number of Pages

-

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1088/0960-1317/24/12/125013

Socpus ID

84914680373 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84914680373

This document is currently not available here.

Share

COinS