On Thursday, September 17, 2020 at 1:29:46 PM UTC-7, John Larkin wrote:> On Thu, 17 Sep 2020 13:09:20 -0700 (PDT), whit3rd <whi...@gmail.com> > wrote:> >> I recall pictures of bipolar transistors emitting weak white light. > > > >Pictures, but perhaps taken with an IR camera? There's a good quantum-mechanics reason to > >expect that a silicon charge-carrier-injection across the bandgap does not make white > >light, but (of course) an IR camera that picks up light is capable of visible-light in white > >or false color as a readout option. > > > >Pictures of emssion is possible. White emission is not. > Of course it is. > > https://www.semitracks.com/reference-material/failure-and-yield-analysis/failure-analysis-die-level/light-emission.php > > Reverse biased pn junctions represent a different situation. When a > small reverse bias is applied to a junction, the depletion region > widens, causing low current but a substantial electric field. As the > reverse bias is increased, the probability that a highly excited > electron will cross the junction increases.Yes, that's certainly possible. The top post, though, specified 'forward bias' and adding in a fluorescence due to higher energy electrons (an electron-beam probe could do it, too) is entirely a different kettle of fish.
Does a wide bandgap JFET glow under forward bias?
Started by ●September 15, 2020
Reply by ●September 17, 20202020-09-17
Reply by ●September 17, 20202020-09-17
Lasse Langwadt Christensen wrote:> with enough power most components do ;)I have never been able to go past the yellow part of the spectrum, although the achieved quantum efficiency was rather impressive and would not be adequately described by the word "weak"... ;-) Best regards, Piotr
Reply by ●September 17, 20202020-09-17
On 2020-09-17 16:09, whit3rd wrote:> On Thursday, September 17, 2020 at 10:35:47 AM UTC-7, John Larkin wrote: >> On Tue, 15 Sep 2020 15:27:38 -0500, "Tim Williams" >> <tiw...@seventransistorlabs.com> wrote: >> >>> Yes. >>> https://www.eevblog.com/forum/projects/transistors-die-pictures/msg3234138/#msg3234138 >>> >>> Tim >> >> I recall pictures of bipolar transistors emitting weak white light. > > Pictures, but perhaps taken with an IR camera? There's a good quantum-mechanics reason to > expect that a silicon charge-carrier-injection across the bandgap does not make white > light, but (of course) an IR camera that picks up light is capable of visible-light in white > or false color as a readout option. > > Pictures of emssion is possible. White emission is not. >Look up the PICA paper I posted. Hot-carrier emission is much bluer than that. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Reply by ●September 17, 20202020-09-17
On 9/17/2020 5:46 PM, Piotr Wyderski wrote:> Tim Williams wrote: > >> Yes. > > Nuts do it as well, so why shouldn't a JFET? > > https://i.imgur.com/WxqQIEB.jpgOhhhh, you didn't mean peanuts or gonads, it seems.> > > https://www.eevblog.com/forum/projects/transistors-die-pictures/msg3234138/#msg3234138 > > > Both effects could probably be combined in a fancy way. > > Best regards, Piotr
Reply by ●September 18, 20202020-09-18
On 17/09/2020 6:35 pm, John Larkin wrote:> On Tue, 15 Sep 2020 15:27:38 -0500, "Tim Williams" > <tiwill@seventransistorlabs.com> wrote: > >> Yes. >> https://www.eevblog.com/forum/projects/transistors-die-pictures/msg3234138/#msg3234138 >> >> Tim > > I recall pictures of bipolar transistors emitting weak white light. > Pease? >Back in 2015 in this group I posted these pics: <https://www.dropbox.com/s/6rkc80amj2aybuk/Veb_Setup.jpg?dl=0> <https://www.dropbox.com/s/2fvi5i6tsphp0yg/Veb_AvalancheLEQ.jpg?dl=0> The e-b in breakdown junction light looked silvery-blue-gray to the human eye but the phone camera image represents a different color so possibly a strong IR component too? piglet
Reply by ●September 18, 20202020-09-18
On Fri, 18 Sep 2020 09:43:39 +0100, piglet <erichpwagner@hotmail.com> wrote:>On 17/09/2020 6:35 pm, John Larkin wrote: >> On Tue, 15 Sep 2020 15:27:38 -0500, "Tim Williams" >> <tiwill@seventransistorlabs.com> wrote: >> >>> Yes. >>> https://www.eevblog.com/forum/projects/transistors-die-pictures/msg3234138/#msg3234138 >>> >>> Tim >> >> I recall pictures of bipolar transistors emitting weak white light. >> Pease? >> > >Back in 2015 in this group I posted these pics: > ><https://www.dropbox.com/s/6rkc80amj2aybuk/Veb_Setup.jpg?dl=0> > ><https://www.dropbox.com/s/2fvi5i6tsphp0yg/Veb_AvalancheLEQ.jpg?dl=0> > >The e-b in breakdown junction light looked silvery-blue-gray to the >human eye but the phone camera image represents a different color so >possibly a strong IR component too? > >pigletAll sorts of semis may glow, but most are potted in black epoxy. It would be cool to zener a photodiode. They are specifically designed for good optical paths into (thus out of) the semiconductor. A forward-biased compound-semi photodiode probably has some, maybe visible, LED effect. -- John Larkin Highland Technology, Inc Science teaches us to doubt. Claude Bernard
Reply by ●September 18, 20202020-09-18
https://www.researchgate.net/publication/327860836_Investigating_SiC_MOSFET_body_diode's_light_emission_as_Temperature-Sensitive_Electrical_Parameter
Reply by ●September 19, 20202020-09-19
On 2020-09-18 21:03, Dmitriy Pshonkin wrote:> https://www.researchgate.net/publication/327860836_Investigating_SiC_MOSFET_body_diode's_light_emission_as_Temperature-Sensitive_Electrical_ParameterMeasuring the photo current, and then displaying the value in mV? The forward voltage of the photo diode will be very depending on temperature (threshold, leakage will vary). The diode is placed on top of the FET gel, so it's temperature will also have varied. Apart from the fun fact that light has been observed, this research is practically useless. It should be mandatory to add a well-qualified electronics engineer to scientific teams dabbling with electronics. And to review teams. Arie
Reply by ●September 19, 20202020-09-19
On Sat, 19 Sep 2020 14:19:17 +0200, Arie de Muynck <no.spam@no.spam.org> wrote:>On 2020-09-18 21:03, Dmitriy Pshonkin wrote: >> https://www.researchgate.net/publication/327860836_Investigating_SiC_MOSFET_body_diode's_light_emission_as_Temperature-Sensitive_Electrical_Parameter > >Measuring the photo current, and then displaying the value in mV? > >The forward voltage of the photo diode will be very depending on >temperature (threshold, leakage will vary). The diode is placed on top >of the FET gel, so it's temperature will also have varied. > >Apart from the fun fact that light has been observed, this research is >practically useless. > >It should be mandatory to add a well-qualified electronics engineer to >scientific teams dabbling with electronics. And to review teams. > >ArieNo, that would remove the substantial amusement available from many scientific papers. -- John Larkin Highland Technology, Inc Science teaches us to doubt. Claude Bernard
Reply by ●September 19, 20202020-09-19
On 2020-09-17 20:20, John S wrote:> On 9/17/2020 5:46 PM, Piotr Wyderski wrote: >> Tim Williams wrote: >> >>> Yes. >> >> Nuts do it as well, so why shouldn't a JFET? >> >> https://i.imgur.com/WxqQIEB.jpg > > > Ohhhh, you didn't mean peanuts or gonads, it seems.I saw that one with the caption, "Extra heavy-duty Russian LED". Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
