Transcript Presentations\Quantum Well Applications

Quantum Well Applications
ECE 4611 – Semiconductors
Presented by:
Joshua MacDonald
& Joel Peterson
29 APRIL 2013
Abstract
In this powerpoint, we present some modern-day
technical applications of quantum well
technology. The small wavelengths made possible
by the well dimensions, which are generally in the
scale of nanometers, are useful in optics for diode
lasers, in measuring devices for IR photo detectors,
and in micro-electronics for high electron mobility
transistor devices. Many of these devices group or
layer quantum wells to improve output or
performance.
Administrative
• Outline
– Review
– General Application
– Applied
• Optics, lasers and detectors
• High speed electronics, transistors
– Key-points
Review (Properties)
• Two-dimensional (mostly) devices
• Discrete energy values
Applications
• Generalities
– Quantum dimensions make very small λ possible.
– Quantum construction means less material,
higher speeds.
Optics
• Diode lasers
• Measuring devices
• Communications
Lasers
• Quantum Well and Quantum Cascade Lasers
– Device geometry(well) is more important than
band structure of the semiconductor.
– Sometimes layered.
IV curve of a QCL
(ALPSLASERS QCL)
Measuring Devices
• Quantum Well IR Photo detector
– Arrays of QW’s “tuned” to a λ.
– Often used in imaging (Medical, Military)
Micro-Electronic
• High Electron Mobility Transistor devices
– Single and Multi Quantum Well structures
– Often employ Quantum Hall Effect
Key Points
• Optical applications exploit low λ possible with QW’s
• Detection devices also employ QW’s because of the
lower λ’s detectable
• HEMT’s speed and performance enabled by
QW(Quantum Hall Effect)
• Devices often layer or group QW’s to improve
characteristics
• There are many proprietary design/material
combinations
References
• http://www.nextnano.de/ (3d device
modeling software) (well structure graphic)
• QCL http://www.alpeslasers.ch/?a=36,37
• QWIP http://www.3-5lab.fr/Scope4-2.htm