Temperature dependent energy relaxation time in AlGaN/AlN/GaN heterostructures

Abstract

a b s t r a c tThe two-dimensional (2D) electron energy relaxation in Al 0.25 Ga 0.75 N/AlN/GaN heterostructures was investigated experimentally by using two experimental techniques; Shubnikov-de Haas (SdH) effect and classical Hall Effect. The electron temperature (T e ) of hot electrons was obtained from the lattice temperature (T L ) and the applied electric field dependencies of the amplitude of SdH oscillations and Hall mobility. The experimental results for the electron temperature dependence of power loss are also compared with the current theoretical models for power loss in 2D semiconductors. The power loss that was determined from the SdH measurements indicates that the energy relaxation of electrons is due to acoustic phonon emission via unscreened piezoelectric interaction. In addition, the power loss from the electrons obtained from Hall mobility for electron temperatures in the range T e > 100 K is associated with optical phonon emission. The temperature dependent energy relaxation time in Al 0.25 Ga 0.75 N/AlN/GaN heterostructures that was determined from the power loss data indicates that hot electrons relax spontaneously with MHz to THz emission with increasing temperatures.

Comprehensive magnetotransport characterization of two dimensional electron gas in AlGaN/GaN high electron mobility transistor structures leading to the assessment of interface roughness

“…It is a usual practice to evaluate m * from the slope of a linear ln(A/T) vs. T fit. 9,12 However, for a tentative value of m * ∼ 0.2 m e for GaN, the value of χ is significantly less than 1.7 at low temperature and in high magnetic field range and hence the ln(A/T) vs. T is not strictly a straight line. 13 We, therefore, utilized Eq.…”

“…This method provided a better resolution of the SdH data for both bands compared to another method of double differentiation. 12 The double differentiation can only eliminate a simple B 2 dependence which may not be strictly valid for cases where multiple carrier types contribute to the parallel conduction. Two distinct oscillatory components of SdH in magnetoresistance, attributed to the carriers in first and second subband according to the frequency of oscillations, are shown for samples A and B in Fig.…”

Low-temperature carrier transport across InGaN multiple quantum wells: Evidence of ballistic hole transport

“…This is a consequence of the increased number of longitudinal optical (LO) phonons. For electrons, LO phonon scattering becomes the dominating scattering mechanism at ∼150 K [17]. Since the scattering time for holes is smaller (it depends on the effective mass m * as m * −1/2 ), the hole-LO phonon scattering mechanism should become dominant at lower temperatures.…”

Investigation of the Hall Effect in Rectangular Quantum Wells With a Perpendicular Magnetic Field in the Presence of a High-Frequency Electromagnetic Wave

“…3 evaluated and plotted versus the temperature at T 0 = 2 K and B n = 3 T. We can see from the figure that this dependence is in accordance with experimental data taken by Tiras and his coworkers recently in the AlGaN/AlN/GaN heterostructures using temperature-dependent classical Hall effect measurements. 20 Theoretically, the relative amplitude versus temperature is also given by [26][27][28] …”