Mid- and Long-IR Broadband Quantum Well Photodetector

A single-stack broadband quantum well infrared photodetector (QWIP) has been developed that consists of stacked layers of GaAs/AlGaAs quantum wells with absorption peaks centered at various wavelengths spanning across the 9-to-11-μm spectral regions. The correct design of broadband QWIPs was a critical step in this task because the earlier implementation of broadband QWIPs suffered from a tuning of spectral response curve with an applied bias. Here, a new QWIP design has been developed to overcome the spectral tuning with voltage that results from nonuniformity and bias variation of the electrical field across the detector stacks with different absorption wavelengths.

In this design, a special effort has been made to avoid non-uniformity and bias tuning by changing the doping levels in detector stacks to compensate for variation of dark current generation rate across the stacks with different absorption wavelengths. Single-pixel photodetectors were grown, fabricated, and tested using this new design.

The measured dark current is comparable with the dark measured current for single-color QWIP detectors with similar cutoff wavelength, thus indicating high material quality as well as absence of performance degradation resulting from broadband design. The measured spectra clearly demonstrate that the developed detectors cover the desired special range of 8 to 12 μm. Moreover, the shape of the spectral curves does not change with applied biases, thus overcoming the problem plaguing previous designs of broadband QWIPs.

This work was done by Alexander Soibel, David Z. Ting, Arezou Khoshakhlagh, and Sarath D. Gunapala of Caltech for NASA’s Jet Propulsion Laboratory. NPO-48398

This Brief includes a Technical Support Package (TSP).

Mid- and Long-IR Broadband Quantum Well Photodetector (reference NPO-48398) is currently available for download from the TSP library.

Please Login at the top of the page to download.


White Papers

HAIs and Chemical Resistance
Sponsored by eastman
All About Aspheric Lenses
Sponsored by edmund optics
Remediation and Prevention of Moisture in Electronics
Sponsored by multisorb technologies
White Papers: Using FPGAs to Improve Embedded Designs
Sponsored by Sealevel
The Changing Face of Robotics
Sponsored by maplesoft
What is Wiring Synthesis?
Sponsored by mentor graphics

White Papers Sponsored By: