InAsN dilute Nitride materials for MIR applications

Introducing just a small amount of nitrogen (<1%) into InGaAs causes a substantial decrease in the alloy bandgap. This striking red-shift attribute has stimulated a great deal of research worldwide into dilute nitrides and corresponding optoelectronic devices for telecommunications. However, as the N content increases the material quality and quantum efficiency become degraded. Together with our collaborators at National Taiwan University (NTU), we are studying the introduction of nitrogen into InAs to reduce the bandgap and access emission wavelengths near 5 μm (300 K) for mid-infrared laser and detector applications. We have grown InAsN on InAs substrates, with N content as high as 2.5% and obtained excellent quantum efficiency with photo-luminescence extending out to 4.5 μm. We also demonstrated that the use of Sb flux during MBE growth increases the incorporation of N and improves the material quality. The development of efficient InAsN and InAsSbN alloys is an important step forward in the practical realisation of improved opto-electronic devices for the mid-infrared spectral range.

Photoluminescence of InAsN (left) and InAsSbN (right) dilute nitride alloys showing efficient emission extending out to 4.5 μm in the mid-infrared.