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.
@article{arxiv.1704.02511,
title = {Thermoelectric bolometers based on ultra-thin heavily doped single-crystal silicon membranes},
author = {Andrey V. Timofeev and Aapo Varpula and Andrey Shchepetov and Kestutis Grigoras and Juha Hassel and Jouni Ahopelto and Markku Ylilammi and Mika Prunnila},
journal= {arXiv preprint arXiv:1704.02511},
year = {2018}
}