We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK


97% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Physics and technology of mid-infrared light em...
View graph of relations

« Back

Physics and technology of mid-infrared light emitting diodes. .

Research output: Contribution to journalJournal article


<mark>Journal publication date</mark>15/03/2001
<mark>Journal</mark>Philosophical Transactions A: Mathematical, Physical and Engineering Sciences
Number of pages20
<mark>Original language</mark>English


There is increasing interest in mid-infrared (mid-IR) light emitting diodes which operate in the 2-5 mum spectral region. Efficient LEDs operating at the characteristic absorption wavelengths of target gases, such as CH4, CO2 and CO, have great potential for-the next generation of optical gas sensors. The fundamental difficulties associated with realizing suitable mid-IR LEDs at different wavelengths, with high continuous wave (CW) output power at room temperature, relate principally to quantum efficiency and optical extraction of the light. Each of these will be briefly considered. Some of the different device designs and techniques used for the suppression of non-radiative Auger recombination and the reduction of Shockley-Read-Hall centres are discussed. Liquid phase epitaxy (LPE) continues to hold a strong position in mid-IR LED technology and many of the best LEDs currently available have been fabricated using this technique. In this respect, the LPE growth of associated InAs(Sb)-based epitaxial structures and their purification is briefly reported. An overview of the 'state of the art' is also given with respect to the application of mid-IR LEDs in practical gas sensors.