Mid-IR, Uncooled Photodetectors Based on Multi-Walled Carbon Nanotubes

Emitech, Inc. proposes an innovative approach aimed at the development of nanoscale, infrared, uncooled photodetectors capable of operating at room temperatures in the wavelength range of 5-15 ƒÝm. A photodiode is composed of carbon nanotubes (CNTs) being in junction with the semiconductor. This new concept is based on the effect of reduced electron-phonon coupling in quasi one-dimensional CNTs, which considerably suppress the thermal noise and enables higher detector operational temperatures. Semiconducting CNTs are known to exhibit the inverse proportional dependence of the band gap on the nanotube diameter. Thus, the variation of the CNT diameter allows to control the detector operational range. Another type of photodetector is based on the bolometric response of suspended CNTs. This new approach is to gain an advantage over traditionally used II-VI and III-V bulk compounds and related nanostructures for IR detection. Simple and cost effective fabrication (wet processing) combined with robust and easy to control electro-optical properties allow making CNT-based detectors with reduced noise, smaller in size, with lower power requirements and at a low fabrication cost. In Phase I we demonstrated the feasibility of the proposed concept. In Phase II we will fabricate multi-spectral, nanoscale, uncooled IR detectors and demonstrate the performance of this innovative technology at the seekers level through laboratory and field tests.