Longitudinal photocurrent spectroscopy of a single GaAs/AlGaAs v-groove quantum wire

Abstract

Modulation-doped GaAs v-groove quantum wires (QWRs) have been fabricated with novel electrical contacts made to two-dimensional electron-gas (2DEG) reservoirs. Here, we present longitudinal photocurrent (photoconductivity/PC) spectroscopy measurements of a single QWR. We clearly observe conductance in the ground-state one-dimensional subbands; in addition, a highly temperature-dependent response is seen from other structures within the v-groove. The latter phenomenon is attributed to the effects of structural topography and localization on carrier relaxation. The results of power-dependent PC measurements suggest that the QWR behaves as a series of weakly interacting localized states, at low temperatures.

Carrier relaxation inGaAsv-groove quantum wires and the effects of localization

“…10 Localized excitons have a key role in producing population inversion for laser emission, 1 and strongly affect the transport characteristics of 1D structures. 11 In this report we present time-integrated and timeresolved PL measurements, and PL-excitation measurements, on an array of GaAs QWRs with a subband separation > k B T room . These measurements reveal a strong temperature dependence of carrier relaxation mechanisms between higher excited states into the ground state of the quantum wires.…”