PHOTOCONDUCTIVITY STUDY OF CRESCENT-SHAPED GAAS GAALAS QUANTUM WIRES GROWN BY FLOW-RATE MODULATION EPITAXY/

We present photoconductivity data on GaAs quantum wires grown on a V-g rooved substrate by flow rate modulation epitaxy. They show that a mod erate excitation power density, similar to 1 W/cm(2), allows the obser vation of the absorption structure of a single GaAs quantum wire embed ded in a p-i-n diode. Furthermore, by increasing the number of active wires inside a diode, the photoconductivity signal is enhanced and add itional details of the absorption structure are evidenced. And, finall y, a rough quantitative agreement is obtained between the experimental absorption transitions and a simple calculation of the one-dimensiona l excitonic states using the envelope function approximation. (C) 1997 American Institute of Physics.