Electrical injection Ga(AsBi)/(AlGa)As single quantum well laser

The Ga(AsBi) material system opens opportunities in the field of high efficiency infrared laser diodes. We report on the growth, structural investigations, and lasing properties of dilute bismide Ga(AsBi)/(AlGa)As single quantum well lasers with 2.2% Bi grown by metal organic vapor phase epitaxy on GaAs (001) substrates. Electrically injected laser operation at room temperature is achieved with a threshold current density of 1.56 kA/cm2 at an emission wavelength of ∼947 nm. These results from broad area devices show great promise for developing efficient IR laser diodes based on this emerging materials system

Growth and characterisation of Ga(NAsSi) alloy by metal-organic vapour phase epitaxy

This paper summarises results of the epitaxial growth of Ga(NAsBi) by metal–organic vapour phase epitaxy (MOVPE) and the subsequent optical and structural characterisations of the samples. Ga(NAsBi)/GaAs multi-quantum well (MQW) samples are grown at 400 °C and single layers at 450 °C on GaAs (001) substrates. Triethylgallium (TEGa), tertiarybutylarsine (TBAs), trimethylbismuth (TMBi) and unsymmetrical dimethylhydrazine (UDMHy) are used as precursors. Secondary ion mass spectrometry (SIMS) shows that the Bi content is independent of the N content in the alloy. It is found that the N content depends on both UDMHy and TMBi supply during growth. High resolution X-ray diffraction (HR-XRD), scanning transmission electron microscopy (STEM) and atomic force microscopy (AFM) measurements show that samples with good crystalline quality can be realised. For samples containing 1.8% Bi and up to 1.8% N grown at 450 °C, photoreflectance spectroscopy (PR) shows a decrease in the band gap with increasing N content of 141±22 meV/% N

MOVPE growth and characterization of quaternary Ga(PAsBi)/GaAs alloys for optoelectronic applications

Dilute bismide Ga(PAsBi)-based structures are promising candidates for highly efficient optoelectronic applications, like the 1 eV sub-cell in multi-junction solar cells or the active region in infra-red laser diodes. The band gap can be tuned independently from the lattice constant, which theoretically enables the deposition of lattice-matched layers in a wide range of band gap energies on GaAs substrate. In this work, firstly, the shifts in the band edge positions as a function of composition that are possible with the Ga(PAs(Bi)) alloy were estimated using the virtual crystal approximation and valence band anti-crossing theory. Secondly, systematic investigations on MOVPE growth of Ga(PAsBi) layers are presented. Finally, we show the first photoluminescence activity of quaternary Ga(PAsBi) and compare the experimental results to theory