Instrumental Exam 2 Flashcards
What are majority carriers?
Electrons or holes which transport electrical conductivity in a semiconductor.
What is penetration depth?
The thickness in which 67% of the photons are absorbed.
What is an n-type semiconductor?
Material that has an excess number of electrons.
What is a p-type semiconductor?
Material that has an excess number of holes.
What is the band gap?
Separation of valence electrons and conductor band for a semiconductor.
What are mobilities?
How fast a carrier moves through the crystal lattice.
What is frequency response?
How rapidly the detector reacts to a time varying optical signal.
What is recombination?
When holes and electrons come together and produce light.
What is a pyroelectric detector?
Single crystalline wafer of a material that is an insulator (dielectric).
What is a bolometer?
IR detector composed of strips of metal or strips of semiconductors.
What is a thermocouple?
IR detector composed of a pair of junctions formed from two pieces of metal.
What is quantum efficiency?
A number of photons generated per electron hole pairs.
What is a depletion layer?
A region with less holes and electrons caused by reverse bias.
What is blue shift?
When transitions move toward shorter wavelength.
What is red shift?
When transitions move toward longer wavelengths.
What is a fluorometer?
When instruments only use filters.
What is internal conversion?
The intermolecular process in which a molecule passes to a lower electronic state without emitting radiation.
