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The rapidly increasing power demand, downsizing of power electronics and material specific limitation of silicon has led to development of AlGaN/GaN heterostructures. Commercial GaN power devices are best available for radio frequency (RF) and high voltage switching applications. Emerging AlxGa1-xN channel based heterostructures are promising to enhance the limits of next generation high voltage GaN power switching devices. In this work, we report on the study of electrical performance of AlGaN channel HEMTs-on-Silicon using various Al content. The fabricated devices exhibited outstanding buffer breakdown electric field above 2.5 MV/cm considering the submicron thin heterostructures grown on silicon substrate. Furthermore, we also experimentally demonstrate high temperature operation of fabricated AlGaN channel HEMTs.

We report on the study of AlGaN/GaN high electron mobility transistors (HEMTs) incorporating an InGaN back‐barrier grown by ammonia‐assisted molecular beam epitaxy (NH3‐MBE). The structural characterizations confirm the good crystalline quality of the heterostructure and the pseudomorphic growth of InGaN. This is also verified by the Hall effect mobility of about 2130 cm2V−1s−1. The associated two‐dimensional electron gas carrier concentration is in the range of 8 × 1012cm−2for heterostructures grown on GaN:Fe‐on‐sapphire templates. Normal DC transistor operation is observed. Similar results have been obtained on silicon substrates. To our knowledge, this is the first demonstration of AlGaN/GaN HEMTs with an InGaN back‐barrier grown by NH3‐MBE.

We investigate in this paper the potential of carbon nanotubes for infrared bolometers. A method to obtain CNT film layer and technological processes to obtain matrix of devices are presented. The electrical characterization of samples establishes the quality of our technology i.e. low contact resistance, and weak dispersion between devices. The potential of carbon nanotubes films as bolometric material is investigated by measuring the thermal dependence of their resistance and by comparison with amorphous silicon (one of the leading material for bolometric applications). Optical measurements of CNT films in the infrared and THz ranges show a relatively high absorption for a few hundreds nanometers thick material. Eventually the infrared (8-12 m) photo-response of a first demonstrator is presented and discussed.