Band structure and optical anisotropy in V-shaped and T-shaped semiconductor quantum wires

We present a theoretical investigation of the electronic and optical properties of V- and T-shaped quantum wires. Valence-band mixing as well as realistic sample geometries are fully included through an accurate and efficient approach that is described here in detail. We investigate the resulting valence-band structure, which shows some significant peculiarities, such as an anomalously large spin splitting in the lowest heavy-hole subband of T-shaped wires. For both classes of wires we obtain good agreement between calculated optical absorption and recent experimental spectra, and we demonstrate that the analysis of optical anisotropy can be used as an effective tool to extract information on valence states, which is usually very difficult to obtain otherwise

Quantum confined stark effect in V-shaped quantum wires

We present the first observation of Quantum Confined Stark Effect in V-shaped InGaAs/GaAs quantum wires grown by MOCVD. P-i-n diodes with vertically staked quantum wires in the intrinsic region exhibit Stark threshold of the order of -2 V at room temperature and low temperature electroluminescence with a threshold current as low as 100 mu A under c.w. injection