# Thermoelectric bolometers based on ultra-thin heavily doped single-crystal silicon membranes

## TL;DR

This paper introduces ultra-thin, heavily doped silicon membrane thermocouple bolometers that enable fast, sensitive detection of low thermal power and infrared radiation at room temperature, with high sensitivity and low noise.

## Contribution

The work demonstrates a novel silicon membrane bolometer design with high sensitivity and fast response, operating near the thermodynamic noise limit.

## Key findings

- Noise equivalent power of 13 pW/rtHz
- Thermal time constant of 2.5 ms
- High Seebeck coefficient of 0.39 mV/K

## Abstract

We present ultra-thin silicon membrane thermocouple bolometers suitable for fast and sensitive detection of low levels of thermal power and infrared radiation at room temperature. The devices are based on 40 nm-thick strain tuned single crystalline silicon membranes shaped into heater/absorber area and narrow n- and p-doped beams, which operate as the thermocouple. The electro-thermal characterization of the devices reveal noise equivalent power of 13 pW/rtHz and thermal time constant of 2.5 ms. The high sensitivity of the devices is due to the high Seebeck coefficient of 0.39 mV/K and reduction of thermal conductivity of the Si beams from the bulk value. The bolometers operate in the Johnson-Nyquist noise limit of the thermocouple, and the performance improvement towards the operation close to the temperature fluctuation limit is discussed.

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Source: https://tomesphere.com/paper/1704.02511