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M. Piller, M.-H. Chien, N. Luhmann, S. Schmid:
"Uncooled nanomechanical photodetector for broad spectral range measurements with picowatt sensitivity";
Poster: Eurosensors 2018, Graz; 2018-09-09 - 2018-09-12; in: "Proceedings - Eurosensors 2018, Graz", MDPI, Vol. 2 (2018), ISSN: 2504-3900.

We present an improved approach for a sensor to detect broadband THz radiation at room temperature with an improved responsivity of currently 14 kW^-1 and a noise equivalent power (NEP) of 12 pW/Hz^1/2 based nanomechanical silicon nitride membrane resonator with defined titanium nitride center absorption pad. The high sensitivity was reached due to optimized local photothermal expansion of absorbing layers on a membrane resonator. The sensitivity could be further improved by the thickness optimization of absorption layer and stress tuning of silicon nitride membrane, with an estimated 50 % of absorption and 1 MPa of prestress in membrane resonator, an expected responsivity of ~360 kW^-1 and NEP of 38 fW/Hz^1/2 could be achieved.