Size effects on polar optical phonon scattering of 1-D and 2-D electron gas in synthetic semiconductors

Abstract

The total scattering rate and the transition probability for electron-phonon interaction in 1-D and 2-D semiconductor materials are calculated in taking into account the finite dimensions of the structure. Although noticeable, size effects on the scattering rate are generally small, with more pronounced features for 1-D structures than for 2-D structures. For 2-D layers, our theory agrees with recent experimental results whereas it contradicts the previous theory predicting large size effects and mass-independent electron-phonon scattering rates. In 1-D structures singularities in the phonon emission rate appear as a natural consequence of the 1-D density of states. However, for high energy the 1-D emission rate is found smaller than the corresponding 3-D rate. An additional consequence of the confinement is the quenching of the phonon absorption rate.

Mobility of 1-D GaAs Quantum Wire Limited by Polar Optic Phonon Scattering

“…The phonon absorption and emission scattering rates have been already been studied for GaAs at 300K by Leburton [9], the phonon emission rate exhibits a singularity at = ℏ as a consequence of the 1-D electron density of states [2,9]. Thus, strong energy relaxation via phonon emission is the dominant scattering which controls mobility in 1-D structures.…”

“…[9]. These results have been used in the calculation for the electron mobility in the GaAs 1-D structure.…”

“…The relation of the scattering rate with the electron energy from Ref. [9] has been used in the calculation of the mobility for GaAs quantum wires. The variation of mobility with the well width for different electron energy has been shown in Fig.3.…”

“…The study of existing literature reveals that mobility calculations in such structures have been done taking into account the scattering mechanisms like impurity scattering [5,7], acoustic phonon scattering [8], optical phonon scattering [2]. It has been established that the dominant scattering mechanism in such structures for the temperature range of interest is the polar optic phonon (POP) scattering [9,10]. The dependence of the mobility on the size of quantum wire has not been studied by many workers.…”

Strong coupling characterisation of quasi-1D polarons in cylindrical QW-wires

“…Since their early prediction [1] and subsequent fabrication [2][3][4][5], there has appeared quite a large interest in phonon-coupling-induced effects and polaronic properties of one-dimensionally confined electrons. Some considerable amount of the literature published within this context has been devoted to the interaction of electrons with bulk-like LO-phonons and the study of the relevant polaron properties [6][7][8][9][10][11][12][13]. The common prediction led by these works is that in quantum wires wherethe electrons are fundamentally quasi-one dimensional (QID) the polaronic binding is far deeper than in comparable quasi-two dimensional systems.…”