Giant bowing of the band gap and spin-orbit splitting energy in GaPBi dilute bismide alloys.

Using spectroscopic ellipsometry measurements on GaPBi/GaP epitaxial layers up to x = 3.7% we observe a giant bowing of the direct band gap ([Formula: see text]) and valence band spin-orbit splitting energy (Δ). [Formula: see text] (Δ) is measured to decrease (increase) by approximately 200 meV (240 meV) with the incorporation of 1% Bi, corresponding to a greater than fourfold increase in Δ in going from GaP to GaPBi.

Thermally Introduced Bismuth Clustering in Ga(P,Bi) Layers under Group V Stabilised Conditions Investigated by Atomic Resolution In Situ (S)TEM.

We report the formation of Bi clusters in Ga(P,Bi) layers during an in situ (scanning) transmission electron microscopy ((S)TEM) annealing investigation. The non-destructive temperature regime in dependence on the tertiarybutylphosphine (TBP) pressure in the in situ cell was investigated to ensure that the results are not distorted by any destructive behaviour of the crystal during the thermal treatment. The following annealing series of the Ga(PBi) and Ga(PBi) layers reveals that the threshold temperature at which the Bi clustering takes place is 600 °C in the Ga(PBi) layer.

An experimental approach for real time mass spectrometric CVD gas phase investigations.

This is a report on the first setup of a recently developed, extremely sensitive and very fast 3D quadrupole ion trap mass spectrometer inline in a metalorganic vapour phase epitaxy (MOVPE) system. This setup was developed ultimately for the decomposition- and the interaction analysis of various established as well as novel metalorganic sources for MOVPE deposition of III/V semiconductors. To make in-situ gas phase and growth interaction analysis on a new level of sensitivity possible without disturbing the MOVPE growth process itself, an optimized experimental connection of the mass spectrometer to the MOVPE system is required.