Navigation Links
Tiny avalanche photodiodes target bioterrorism agents

After the anthrax attacks in the United States in 2001 the threat of a larger and more deadly bioterrorism attack -- perhaps from smallpox, plague or tularemia -- became very real. But the ability to detect such biological agents and rapidly contain an attack is still being developed.

In a significant finding, researchers at Northwestern University's Center for Quantum Devices have demonstrated solar-blind avalanche photodiodes (APDs) that hold promise for universal biological agent detection. Once optimized, these sensitive detectors could be combined with the ultraviolet light-emitting diodes (LEDs) already pioneered by the Center for Quantum Devices to create an inexpensive detection system capable of identifying the unique spectral fingerprints of a biological agent attack.

The Northwestern team, led by center director Manijeh Razeghi, became the first to demonstrate 280 nanometer APDs. These devices, based on aluminum gallium nitride (AlGaN) compound semiconductors, have a photocurrent gain of more than 700.

The tiny-sized APDs should be capable of efficient detection of light with near single photon precision. Previously, photomultiplier tubes (PMTs) were the only available technology in the short wavelength UV portion of the spectrum capable of this sensitivity. These fragile vacuum tube devices are expensive and bulky, hindering true systems miniaturization.

The APD technology may see further use in the deployment of systems for secure battlefield communication. Wavelengths around 280 nanometers are referred to as the solar-blind region; in this region, the UV light is filtered out by the ozone layer providing for a naturally low background signal. Solar-blind APDs are intrinsically able to take advantage of this low background level, while PMTs must use external filters to become solar-blind. This makes secure battlefield communication possible utilizing a combination of compact, inexpensive UV LEDs and UV APDs both developed at the Center for Quantum Devices.

The technology for the realization of solar-blind APDs is based on wide bandgap AlGaN compound semiconductors. To date, no semiconductor-based solar-blind APDs have been reported. This is due to numerous difficulties pertaining to the crystal growth of AlGaN compound semiconductors.

The major obstacle in demonstrating high performance solar-blind APDs is the high number of crystalline defects present in the AlGaN semiconductor material. However, researchers at the Center for Quantum Devices have been able to realize high-quality AlGaN so as to demonstrate avalanche gain in the solar-blind region.

Northwestern's results were presented recently by Razeghi at the APD workshop organized by Henryk Temkin, a new program manager at the Defense Advanced Research Projects Agency (DARPA).


'"/>

Source:Northwestern University


Related biology news :

1. Scientists find evidence of catastrophic sand avalanches, sea level changes in Gulf of Mexico
2. New binding target for oncogenic viral protein
3. Ancient olfaction protein is shared by many bugs, offering new pest control target
4. A bacterial genome reveals new targets to combat infectious disease
5. Muscle-targeted gene therapy reverses rare muscular dystrophy in mice
6. Researchers identify target for cancer drugs
7. Study reveals candidate targets for anti-retroviral therapeutics
8. MUHC researchers make cancer target breakthrough
9. Future diabetes drugs may target new protein interaction
10. Smart drug targets deadly brain cancer
11. NHGRI targets 12 more organisms for genome sequencing
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:2/9/2016)... -- Vigilant Solutions announces today that an agency used its ... lead in a difficult homicide case. The agency then used ... suspect vehicle. Due to the ongoing investigation, the agency name ... the agency,s request. --> --> ... found deceased at an intersection here in the City. He ...
(Date:2/3/2016)... 2016 --> ... "Automated Fingerprint Identification System Market by Component (Hardware and ... & Finance, Government, Healthcare, and Transportation) and Geography - ... is expected to be worth USD 8.49 Billion by ... and 2020. The transformation and technology evolution from the ...
(Date:2/2/2016)... YORK , Feb. 2, 2016 ... of that Rising Market Are you interested ... analysis forecasts revenues for checkpoint inhibitors. Visiongain,s report ... market, submarket, product and national level. Avoid ... discover what progress, opportunities and revenues those emerging ...
Breaking Biology News(10 mins):
(Date:2/10/2016)... ... February 10, 2016 , ... HOLLOWAY AMERICA, a leading custom ... Rocky Mountain Chapter 21st Annual Vendor Exhibition on Thursday, February 18, 2016. The ... for its annual event, which will run from 3:00 p.m. - 8:30 p.m. ...
(Date:2/10/2016)... CA (PRWEB) , ... February 10, 2016 , ... ... Multiplex Testing (PROMPT), a research registry built on the secure online PatientCrossroads platform, ... 2014. More than 1,600 participants have joined the PROMPT study, which seeks to ...
(Date:2/10/2016)... ... February 10, 2016 , ... Cenna Bioscience Inc., an emerging biopharmaceutical company ... disease, announced today it has been selected to present at the Cavendish Global Health ... Beach, Florida. The purpose of the Forum is to help family offices and ...
(Date:2/9/2016)... 2016  Regenicin, Inc. (OTC Bulletin Board: ... development and commercialization of regenerative cell therapies to ... recently reported the Company,s operating results for 2015 ... Lonza America , Inc. (the "Lonza ... in the process of consummating an agreement to ...
Breaking Biology Technology: