Multiple functional UV devices based on III-Nitride quantum wells for biological warfare agent detection
2009 (English)In: GALLIUM NITRIDE MATERIALS AND DEVICES IV, 2009, 721627-1-721627-9 p.Conference paper (Refereed)
We have demonstrated surface normal detecting/filtering/emitting multiple functional ultraviolet (UV) optoelectronic devices based on InGaN/GaN, InGaN/AlGaN and Al xGa1-xN/AlyGa1-yN multiple quantum well (MQW) structures with operation wavelengths ranging from 270 nm to 450 nm. Utilizing MQW structure as device active layer offers a flexibility to tune its long cut-off wavelength in a wide UV range from solar-blind to visible by adjusting the well width, well composition and barrier height. Similarly, its short cut-off wavelength can be adjusted by using a GaN or AlGaN block layer on a sapphire substrate when the device is illuminated from its backside, which further provides an optical filtering effect. When a current injects into the device under forward bias the device acts as an UV light emitter, whereas the device performs as a typical photodetector under reverse biases. With applying an alternating external bias the device might be used as electroabsorption modulator due to quantum confined Stark effect. In present work fabricated devices have been characterized by transmission/absorption spectra, photoresponsivity, electroluminescence, and photoluminescence measurements under various forward and reverse biases. The piezoelectric effect, alloy broadening and Stokes shift between the emission and absorption spectra in different InGaN- and AlGaN-based QW structures have been investigated and compared. Possibilities of monolithic or hybrid integration using such multiple functional devices for biological warfare agents sensing application have also be discussed.
Place, publisher, year, edition, pages
2009. 721627-1-721627-9 p.
, Proceedings of SPIE-The International Society for Optical Engineering, ISSN 0277-786X
III-Nitride quantum wells, UV photodiode and biological warfare agent detection
IdentifiersURN: urn:nbn:se:kth:diva-48949DOI: 10.1117/12.808469ISI: 000285752800036ScopusID: 2-s2.0-65349142480OAI: oai:DiVA.org:kth-48949DiVA: diva2:458972
Conference on Gallium Nitride Materials and Devices IV. San Jose, CA. JAN 26-29, 2009
QC 201111292011-11-242011-11-242011-11-29Bibliographically approved