ORC Seminar Series

Prof Anthony Krier
Physics Department, Lancaster University

Date: Wednesday 21 November 2007
Time: 2pm
Venue: Building 2, Room 1039, Lecture Theatre K

Mid-infrared semiconductor LEDs and lasers operating in the 2-5 µm spectral range are of interest for a wide variety of applications, including; chemical process control, environmental pollution monitoring, non-invasive medical diagnosis, tunable IR spectroscopy, laser surgery and free space optical communications. However, the advantages of this wavelength range have yet to be fully exploited due to the lack of suitable room temperature, high emittance sources. The principal challenges relate to the  non-radiative recombination associated with Shockley-Read-Hall recombination in LEDs and Auger recombination at higher injection levels in diode lasers. Optical extraction and inter-valence-band absorption present addditional problems. The seminar will present an overiew of the mid-infrared LEDs and diode lasers being developed at Lancaster. Devices produced from both the  liquid phase and using molecular beam epitaxial growth will be described, including recent results from quantum dot structures. 

Tony Krier is professor of Physics at Lancaster University. He is head of the Condensed Matter Division and leader of the Mid-infrared Optoelectronics research group which he founded in 1990. Since then he has worked extensively on mid-infrared materials and devices and has published more than 120 papers. His group has produced a variety of novel materials and devices including, InAsSb quantum dot LEDs grown by liquid phase epitaxy and mid-infrared ring lasers operating near 3 µm. In 1996 he founded the mid-infrared materials & devices (MIOMD) international conference series. He is also the founder and co-ordinator of the mid-infrared network. His current research interests include electro- and photoluminescence of GaInAsSbP/InAs(GaSb) heterostructures and the fabrication of quantum dot and quantum well LEDs, lasers and detectors for the 2-5 µm spectral range.