A definition in semiconductor physics, carrier lifetime is defined as the average time it takes for a minority carrier to recombine. The process through which this is done is typically known as minority carrier recombination.
The energy released due to recombination can be either thermal, thereby heating up the semiconductor (thermal recombination or non-radiative recombination, one of the sources of waste heat in semiconductors), or released as photons (optical recombination, used in LEDs and semiconductor lasers).
Carrier lifetime plays an important role in bipolar transistors and solar cells.
In indirect band gap semiconductors, the carrier lifetime strongly depends on the concentration of recombination centers. Gold atoms act as highly efficient recombination centers, silicon for some high switching speed diodes and transistors is therefore alloyed with a small amount of gold. Many other atoms, e.g. iron or nickel, have similar effect.
Read more about Carrier Lifetime: Carrier Lifetime in Semiconductor Lasers
Famous quotes containing the words carrier and/or lifetime:
“When toddlers are unable to speak about urgent matters, they must resort to crying or screaming. This happens even with adults. The voice is the carrier of emotion, and when speech fails us, we need to cry out in whatever form we can to convey our meaning. Often, what passes for negativism is really the toddler’s desperate effort to make herself understood.”
—Alicia F. Lieberman (20th century)
“The greatest part of each day, each year, each lifetime is made up of small, seemingly insignificant moments. Those moments may be cooking dinner...relaxing on the porch with your own thoughts after the kids are in bed, playing catch with a child before dinner, speaking out against a distasteful joke, driving to the recycling center with a week’s newspapers. But they are not insignificant, especially when these moments are models for kids.”
—Barbara Coloroso (20th century)