Wavelength dependent negative and positive persistent photoconductivity in Sn δ-doped GaAs structures

A photoluminescence study of δ-doped GaAs

Samples of GaAs 8-doped with beryllium have been studied with photoluminescence. With a lightly doped sample, (2 x 1016 Be atoms per m2) a spectral feature is observed which can be interpreted as caused by radiative recombinations between spatially non-confined conductionband electrons and acceptor-related holes forming a miniband system confined spatially to the &doped region. With higher dens...

Lattice relaxed impurity and persistent photoconductivity in nitrogen doped 6HSiC

X-ray induced persistent photoconductivity in Si-doped Al0.35Ga0.65As

We demonstrate that x-ray irradiation can be used to induce an insulator–metal transition in Si-doped Al0.35Ga0.65As, a semiconductor with DX centers. The excitation mechanism of the DX centers into their shallow donor state was revealed by studying the photoconductance along with fluorescence. The photoconductance as a function of incident x-ray energy exhibits an edge both at the Ga and As K ...

Photoconductivity Relaxation Mechanisms of InGaAs/GaAs Quantum Dot Chain Structures

An experimental study of the photoconductivity time decay in InGaAs/GaAs quantum dot chain structures is reported. Different photoconductivity relaxations resulting from spectrally selecting photoexcitation of InGaAs QWR or QDs as well as GaAs spacers were measured. The photoconductivity relaxation after excitation of 650 nm follows a stretched exponent with decay constant dependent on morpholo...

Laser-induced etching of Cr–O doped GaAs and wavelength dependent photoluminescence

The laser-induced chemical etching mechanism of Cr–O doped GaAs (1 0 0) substrate in 40% HF-H2O solution is explained by the generation of e–h pairs through defect states in the presence of sub-bandgap photon illumination by using a Nd:YAG Laser (λ ∼ 1.06 m). The central feature of the laser etching technique is pits initiation by surface defects. The etched GaAs samples are characterised by ph...