Anharmonicity Induced Faster Decay of Hot Phonons in Rutile TiO2 Nanorods: A Raman Spectromicroscopic study

Temperature dependent Raman spectromicroscopy from rutile TiO2 nanorods has been studied here to understand the effect of thermal perturbations on different Raman active phonon modes. The TiO2 nanorods, characterized using...

Electron transport in a coupled GaN/AlN/GaN channel of nitride HFET

Longitudinal hot-electron transport is investigated for the alloy-free AlGaN/AlN/{GaN/AlN/GaN} heterostructure at electric fields up to 380 kV/cm. The structure featured a coupled channel with a camelback electron density profile. The hot-electron drift velocity in the coupled channel is estimated as ~1.5×107 cm/s and is ~50% higher as compared with the standard AlN-spacer GaN 2DEG channel. The HFET with the pristine 2DEG density of 1.75×1013 cm–2 confined in the coupled channel demonstrates the optimal frequency performance in terms of electron velocity at a relatively low gate bias of VGS = –1.75 V. These results are consistent with the ultra-fast decay of hot phonons.

KINETIC CORRELATION IN NON-EQUILIBRIUM FERMION–BOSON GAS

We present a theoretic treatment of particle–particle correlation in a non-equilibrium fermion–boson gas subjected to strong electric field. The detailed description is based on an example of hot electrons and hot phonons in a solid under quasi-classical approach in terms of Boltzmann-like kinetic equations. We develop the mathematical apparatus, based on diagrammatic approach, for quantitative investigation of the flows of correlated particles. Non-trivial terms are resolved, and the correlations crucial for electric fluctuations are discussed.