Light emitting Zener...

Thread Starter

Externet

Joined Nov 29, 2005
1,816
Hi.
Does such animal exist ? A Zener diode emitting light when the zener knee conducts ? Like a Zener and an LED in series in the same package :rolleyes:
 

dl324

Joined Mar 30, 2015
14,303
Not yet. Silicon junctions have been shown to emit light during avalanche breakdown, but not enough to be useful. Silicon emitters would have some useful applications in integrated circuits.

The phenomenon was observed before integrated circuits were invented.
 

panic mode

Joined Oct 10, 2011
2,110
all PN junctions emit light when forward biased. they may not be efficient and radiation may not be in the visible spectrum but they all do.
 

nsaspook

Joined Aug 27, 2009
9,435
In a high voltage Zener during avalanche breakdown, carrier recombination can produce visible EM radiation. I would think the silicon structure requirements for visible photon emission and voltage regulation might not be exactly mutual.
https://www.intechopen.com/chapters/47465
Since electron-hole pairs are produced during avalanche breakdown, some radiative recombination occurs. Both the electrons and the holes can be heated by the electric field. Since it is attributed to the hot-carrier population under the condition of avalanche breakdown, the light emission can be used for high-speed light-emitting devices, high-speed light amplifiers, and the analytic investigation of hot carrier distribution
https://www.laserfocusworld.com/las...-optical-coupling-in-cmos-integrated-circuits
 
Last edited:

crutschow

Joined Mar 14, 2008
29,466
Does such animal exist ? A Zener diode emitting light when the zener knee conducts ? Like a Zener and an LED in series in the same package
Silicon junctions generally emit radiation in the near IR.
For visible light, you need higher band-gap semiconductor material like gallium, which are not generally compatible with silicon junction fabrication.

Why do you want a Zener to emit light?
 

panic mode

Joined Oct 10, 2011
2,110
if indication that zener is conducting is useful (clamping voltage) then it is not a problem to add indicator LED and perhaps adjust zener rating. but this is rather obscure and rare requirement so i do not see justification to produce single component that includes both of mentioned devices. one can easily make own assembly that does just that. same is done with switching regulators that are replacing LM7805. couple of SMD components on a tiny PCB and you are done.
 
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