Wydarzenia

Seminarium Fizyki Politechniki Wrocławskiej

Pushing the boundaries of III-Vs: Exploiting Bismide alloys for near- and mid-infrared photonics

prof. Stephen Sweeney

Advanced Technology Institute and Department of Physics, University of Surrey, Guildford

In this talk I will describe current interest in pushing the boundaries of III-V semiconductor materials and in particular why adding Bismuth to semiconductors such as GaAs offers several advantages in terms of producing devices such as semiconductor lasers. The incorporation of Bismuth in GaAs has recently been shown to cause a large band gap “bowing” allowing narrow band gap materials to be produced on GaAs. In addition, the large size of Bismuth atoms also gives rise to a large spin-orbit splitting. This opens-up interesting new possibilities for efficient photonic devices, such as near- and mid-infrared lasers which are more thermally stable and less susceptible to problematic losses. Since Bismuth principally influences the valence band, while nitrogen influences the conduction band, combining Bismuth and Nitrogen in III-V alloys offers huge potential for engineering the conduction and valence band offsets, the band gap and spin-orbit splitting, with wide scope for the design of photonic devices. Challenges in achieving this including recent results will be discussed.