AVS 47th International Symposium
    Photonics Tuesday Sessions
       Session PH-TuP

Paper PH-TuP4
Integrated Optoelectronic Sensor Based on GaN

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: D. Starikov, University of Houston
Authors: D. Starikov, University of Houston
E. Kim, University of Houston
C. Boney, University of Houston
J.-W. Um, University of Houston
I. Hernandez, University of Houston
N. Medelci, University of Houston
A. Bensaoula, University of Houston
Correspondent: Click to Email
An integrated optoelectronic sensor based on GaN grown on sapphire by RF-assisted MBE is presented. The sensor combines inter-digitated line arrays of light emitting diodes (LEDs) and photodiodes based on Schottky barriers and fabricated in a single technological process. Under reverse bias the LEDs exhibit broad-spectrum avalanche emission with a strong band in the range from 365 to 475 nm. At forward bias the LED emission is more intense and forms a band from 400 to 600 nm. The photodiodes are sensitive in a spectral range from at least 250 to 400 nm. In the absorption/reflection mode the sensor operation is based on the spectral match between the avalanche emission and the photodiode sensitivity in the range from 365 to 400 nm. Using this set up, Acridine concentration measurements in aqueous solutions were performed using the absorption band of 300-450 nm. The fluorescence measurements were based on detection of the delayed fluorescence emission measured from alcohol solutions of Fluoran dye in the range from 290 to 320 nm under excitation with short optical pulses from the LEDs. The working range and the sensitivity of the sensor were evaluated using preset calibrated concentrations and will be presented during the presentation. This work was funded by Institute of Space Systems and Operations, NASA, and Texas ATP. The material is based in part upon work supported by the Texas Space Grant Consortium.