A study of electric transport in n- and p-type modulation-doped GaInNAs/GaAs quantum well structures under a high electric field

Abstract

We present the results of longitudinal carrier transport under a high electrical field in n-and p-type modulation-doped Ga 0.68 In 0 . 32 N y As 1−y /GaAs (y=0.009, 0.017) quantum well (QW) structures. Nitrogen composition-dependent drift velocities of electrons are observed to be saturated at´-1.7 10 cm s 7 1 and´-1.2 10 cm s 7 1 at 77 K for the samples with y=0.009 and y=0.017, respectively, while the drift velocities of holes do not saturate but slightly increase at the applied electric field in the range of interest. The hole drift velocity is observed to be higher than the electron drift velocity. The electron mobility exhibits an almost temperatureindependent characteristic. On the other hand, the hole mobility exhibits a conventional temperature dependence of modulation-doped QW structures. As the temperature increases, the drift velocity of the electrons exhibits an almost an temperature-insensitive characteristic, but, on the other hand, for holes, drift velocity decreases approximately from 10 7 -10 6 cm s −1 . It is observed that the drift velocities of electrons and holes are N-dependent and suppressed at higher electric fields. Furthermore, experimental results show that there is no evidence of negative differential velocity (NDV) behaviour for both n-and p-type samples. To explore the observed electron and hole drift velocity characteristic at high electric fields, we use a simple theoretical model for carrier transport, which takes into account the effect of non-drifting hot phonons. The mobility mapping technique (comparison method) is used to extract hot hole temperature in order to employ it in the non-drifted phonon distribution and to obtain the drift velocity-electric field curves. Then hot electron temperatures are obtained from the drift velocity-electric field curves as a fit parameter using non-drifted hot phonon dynamics. The analytical model is wellmatched to the experimental u d -E curves, indicating that carrier-hot phonon scattering is the main reason for suppressing the NDV mechanism in GaInNAs/GaAs QW structures with a carrier density higher than 10 17 cm −3 .

Weak localization competes with the quantum oscillations in a natural electronic superlattice: The case of Na1.5(PO2)4(WO3Kolincio1, Pérez2, Canadell3 et al. 2020Phys. Rev. B1100View full textAdd to dashboardCite

“…However, due to the decrease of the WL contribution with magnetic field and with the restricted condition ω c τ (k F ) −1 (k F is the Fermi momentum and l the electronic mean free path), a crossover can be observed between these two quantum processes, whose magnetic field range has been related to interaction effects [11]. This crossover has been previously observed in rare systems showing strong 2D characteristics: 2D electron gas heterostructures with high mobilities [12], quantum wells [11,13,14], and graphene [15,16]. We show here that both WL and SdH are observed in a single crystal whose 2D character arises from the carrier confinement in conducting layers with a thickness of a few atomic planes.…”

Weak localization competes with the quantum oscillations in a natural electronic superlattice: the case of Na$_{1.5}$(PO$_2$)$_4$(WO$_3$)$_{20}$

“…However, due to the decrease of the WL contribution with magnetic field and with the restricted condition ω c τ ≤ (k F ℓ) −1 (k F is the Fermi momentum and l the electronic mean free path), a crossover can be observed between these two quantum processes, whose magnetic field range has been related to interaction effects [11]. This crossover has been previously observed in rare systems showing strong 2D characteristics: 2D electron gas heterostructures with high mobilities [12], quantum wells [11,13,14], and graphene [15,16]. We show here that both WL and SdH are for the first time observed in a single crystal whose 2D character arises from the carriers confinement in conducting layers with a thickness of few atomic planes.…”

Velocity-field characteristics of MgxZn1−xO/ZnO heterostructures

“…On the other hand, the characteristics of HEMTs is not only determinded by conductance of the transistor channel in a weak electric field, but also depends on its variation with increasing field strength. Therefore, the field dependence of the electron drift velocity is very important to device analysis and design [5][6][7][8][9].…”