Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Electrical and Computer Engineering

Theses and Dissertations

Theses/Dissertations

2014

HFET

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Piezotransistive Iii-V Nitride Microcantilever Based Mems/Nems Sensor For Photoacoustic Spectroscopy Of Chemicals, Abdul Hafiz Ibne Talukdar Dec 2014

Piezotransistive Iii-V Nitride Microcantilever Based Mems/Nems Sensor For Photoacoustic Spectroscopy Of Chemicals, Abdul Hafiz Ibne Talukdar

Theses and Dissertations

Microcantilevers are highly attractive as transducers for detecting chemicals, explosives, and biological molecules due to their high sensitivity, micro-scale dimensions, and low power consumption. Though optical transduction of the mechanical movement of the microcantilevers into an electrical signal is widely practiced, there is a continuous thrust to develop alternative transduction methods that are more conducive to the development of compact miniaturized sensors. Piezoelectric and piezoresistive transduction methods are two of the most popular ones that have been utilized to develop miniaturized sensor systems. Piezoelectric cantilevers, which are commonly made of PZT film, have demonstrated very high sensitivity; however, they suffer …


Electron – Phonon Interaction In Multiple Channel Gan Based Hfets: Heat Management Optimization, Romualdo A. Ferreyra Jan 2014

Electron – Phonon Interaction In Multiple Channel Gan Based Hfets: Heat Management Optimization, Romualdo A. Ferreyra

Theses and Dissertations

New power applications for managing increasingly higher power levels require that more heat be removed from the power transistor channel. Conventional treatments for heat dissipation do not take into account the conversion of excess electron energy into longitudinal optical (LO) phonons, whose associated heat is stored in the channel unless such LO phonons decay into longitudinal acoustic (LA) phonons via a Ridley path. A two dimensional electron gas (2DEG) density of ~5×1012cm-2 in the channel results in a strong plasmon–LO phonon coupling (resonance) and a minimum LO phonon lifetime is experimentally observed, implying fast heat removal from …