A transient electron transport analysis of bulk wurtzite zinc oxide

Abstract

A three-valley Monte Carlo simulation approach is used in order to probe the transient electron transport that occurs within bulk wurtzite zinc oxide. For the purposes of this analysis, we follow O’Leary et al. [Solid State Commun. 150, 2182 (2010)], and study how electrons, initially in thermal equilibrium, respond to the sudden application of a constant applied electric field. We find that for applied electric field strength selections in excess of 300 kV/cm that an overshoot in the electron drift velocity is observed. An undershoot in the electron drift velocity is also observed for applied electric field strength selections in excess of 700 kV/cm, this velocity undershoot not being observed for other compound semiconductors, such as gallium arsenide and gallium nitride. We employ a means of rendering transparent the electron drift velocity enhancement offered by the transient electron transport, and then use the calculated dependence of the peak transient electron drift velocity on the applied electric field for the design optimization of short-channel high-frequency electron devices.

A 2015 perspective on the nature of the steady-state and transient electron transport within the wurtzite phases of gallium nitride, aluminum nitride, indium nitride, and zinc oxide: a critical and retrospective review

“…This result suggests that the lowfield electron drift mobility associated with a semiconductor will diminish as the E o energy gap is increased. [199] for the case of wurtzite InN, and Hadi et al [196] for the case of wurtzite ZnO. This table has been modified from Table 2 of O'Leary et al [110] and Table 2 of Hadi et al [204].…”

“…This table has been modified from Table 1 of O'Leary et al [110] and Table 1 of Hadi et al [204]. Copyright permission was obtained from Springer a Parameters from O'Leary et al [110] b Parameters from O'Leary et al [110] c Parameters from Hadi et al [199] d Parameters from Hadi et al [196] energy gap. The material and band structural parameters, used for this critical comparative analysis, are drawn from Tables 1 and 2, Adachi [15], Hadi et al [204], and Sze and Ng [227].…”

“…This table has been modified from Table 2 of O'Leary et al [110] and Table 2 of Hadi et al [204]. Copyright permission was obtained from Springer a Parameters from O'Leary et al [110] b Parameters from O'Leary et al [110] c Parameters from Hadi et al [199] d Parameters from Hadi et al [196] J In Fig. 5, we plot the polar optical phonon energy, hx o , as a function of the 300 K E o energy gap corresponding to the materials considered in this critical comparative analysis.…”

“…Table 2. These parameter selections are also primarily drawn from O'Leary et al [110] for the cases of wurtzite GaN and wurtzite AlN, Hadi et al [199] for the case of wurtzite InN, and Hadi et al [196] for the case of wurtzite ZnO [224,225]. 19 The material and band structural parameters, corresponding to zinc-blende GaAs, are primarily drawn from Littlejohn et al [224] and Blakemore [226].…”

“…The material parameter selections, used for our simulations of the electron transport within the wurtzite phases of GaN, AlN, InN, and ZnO, are as specified in Table 1 [199] for the case of wurtzite InN, and Hadi et al [196] for the case of wurtzite ZnO. The band structural parameter selections, 15 The longitudinal and transverse sound velocities are equal to ffiffiffiffi ffi C l q s and ffiffiffiffiffi C t q s ; respectively, where C l and C t denote the respective elastic constants and q represents the mass density.…”