Thermoelectric thermal detectors based on ultra-thin heavily doped single-crystal silicon membranes

• DOI: 10.1063/1.4989683
• Publication Date: 2017-06-26T13:00:39Z
• Authors: Aapo Varpula; Andrey V. Timofeev; Andrey Shchepetov; Kestutis Grigoras; Juha Hassel; Jouni Ahopelto; Markku Ylilammi; Mika Prunnila
• Keywords: Thermocouple; Noise-equivalent power; Scanning thermal microscopy; Johnson–Nyquist noise

We present thermal detectors based on 40 nm-thick strain tuned single crystalline silicon membranes shaped into a heater area supported by narrow n- and p-doped beams, which also operate as thermocouple. The electro-thermal characterization of the devices reveals noise equivalent power 13 pW/Hz1/2 time constant 2.5 ms. high sensitivity is due to Seebeck coefficient 0.39 mV/K reduction conductivity Si beams from bulk value. performance enables fast sensitive detection low levels infrared radiation at room temperature. in Johnson-Nyquist limit thermocouple, improvement towards operation close temperature fluctuation discussed.