GaN ballistic or quasi-ballistic electron devices require short transit distances in the order of a mean free path to avoid longitudinal optical phonon LO emission. Vertical current flow by design takes full advantage of the abrupt and thin layers grown by molecular beam epitaxy (MBE). Moreover, crystal orientation becomes important when ballistic transport is involved since bandstructure depen...

We have developed a new self-aligned gate technology for InGaAs High Electron Mobility Transistors with non-alloyed Mo-based ohmic contacts and a very low parasitic capacitance gate design. The new process delivers a contact resistance of 7 Ohm-μm and a source resistance of 147 Ohm-μm. The nonalloyed Mo-based ohmic contacts show excellent thermal stability up to 600 °C. Using this technology, w...

We report the x-ray photocurrent response of a coplanar chemical vapor deposition diamond detector fabricated using a metal-less graphitic ohmic contact. Ion implantation of 70 keV boron ions to a dose of 2 1016 cm−2 was performed through a patterned photoresist to produce a coplanar graphitic contact structure. The device photocurrent showed a fast response to pulsed x-ray irradiation, and sho...

A new single nanowire based nanosensor is demonstrated for illustrating its ultrahigh sensitivity for gas sensing. The device is composed of a single ZnO nanowire mounted on Pt electrodes with one end in Ohmic contact and the other end in Schottky contact. The Schottky contact functions as a "gate" that controls the current flowing through the entire system. By tuning the Schottky barrier heigh...

The general form of interfacial contact resistance was derived for organic thin-film transistors (OTFTs) covering various injection mechanisms. Devices with a broad range of materials for contacts, semiconductors, and dielectrics were investigated and the charge injections in staggered OTFTs was found to universally follow the proposed form in the diffusion-limited case, which is signified by t...