Distributed infrared sensors on flexible
and rigid substrates for room temperature infrared, pressure, and flow sensing
applications.Uncooled Infrared Detectors
Directors: Professors Donald P. Butler and Zeynep Celik-Butler
A radiation detector is a device that produces an output signal, which depends on the amount of radiation hitting the active region of the detector. In general, infrared (IR) sensors can be classified as thermal or photon type of detectors. Photon type detectors such as photovoltaic or photoconductive sensors operate on the principles of direct electron - photon interaction. They provide superior sensitivity and response speed. However, photon detectors typically require costly cryogenic operation to minimize the noise sources to obtain the high relative sensitivity. On the other hand, thermal detectors convert incident radiation into heat, thereby raising the temperature of the detector element. This change in temperature is then converted to an electrical signal that can be amplified and displayed. Thermal detectors are capable of responding to a wide range of wavelengths without appreciable variation in responsivity. Thermal detectors display high sensitivity at room temperature to permit imaging and radiometry applications.
There are 3 primary types of thermal detectors: bolometers whose resistance changes with temperature, pyroelectric detectors where the spontaneous polarization or surface charge changes with temperature, and thermopile detectors that utilize the Seebeck or thermoelectric effect.
The UTA Microsensors Research Laboratory has the following focus:
Distributed infrared sensors on flexible
and rigid substrates for room temperature infrared, pressure, and flow sensing
applications.
The investigation of noise mechanisms in uncooled infrared detectors
Novel micromachined structures for uncooled infrared detectors,
including self-supporting IR sensing materials.
Integration of IR microsensors
with micromachined IR sources for microspectroscopy applications.
|
SEM micrograph of 40 mm x 40 mm self-supporting Y-Ba-Cu-O microbolometers with Ti electrode arms and Au contacts. The detectors were micromachined using a standard polyimide sacrificial layer. |
|
Properties and transport in semiconducting Y-Ba-Cu-O.
1st Generation Y-Ba-Cu-O Microbolometers. (Bulk-micromachined)
2nd Generation Y-Ba-Cu-O Microbolometers. (Surface micromachined with MgO sacrificial layer)
3rd Generation Y-Ba-Cu-O Microbolometers. (Self-supporting, low thermal mass structures using polyimide sacrificial layer)
Broad Band Microbolometers. (large area microbolometers covering the 0.3 mm to 100 mm optical band)
Ferroelectricity and Pyroelectricity in Y-Ba-Cu-O.
Sponsors
This work is supported by the National Science Foundation, the Army Research Office, NASA-Langley, and Raytheon
