A breakthrough in low voltage blue LEDs announced recently this manages
to produce 2.7eV blue photons from an applied voltage of 1.47v! It is
the chemical equivalent of a Cockcroft-Walton voltage doubler.

https://www.sciencedaily.com/releases/2023/09/230920110657.htm

Or for more details the Nature paper (may be behind a paywall)

https://www.nature.com/articles/s41467-023-41208-7

It is a very cunning design and chemistry.

--
Martin Brown

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Martin Brown <'''newspam'''@nonad.co.uk> wrote:

A breakthrough in low voltage blue LEDs announced recently this manages
to produce 2.7eV blue photons from an applied voltage of 1.47v! It is
the chemical equivalent of a Cockcroft-Walton voltage doubler.

https://www.sciencedaily.com/releases/2023/09/230920110657.htm

Or for more details the Nature paper (may be behind a paywall)

https://www.nature.com/articles/s41467-023-41208-7

It is a very cunning design and chemistry.

Fun. I’ll have to try digging up a copy of the original paper.

Could conceivably be important if the quantum efficiency is decent and the drive circuitry isn’t too horrible. (The QE obviously can’t exceed 50%.)

The Science Daily article claims the usual sorts of stuff about battery
voltage being this fundamental limitation, as though there were no such
things as SMPSes.

It’s far from clear that it’s some huge win needing 2x the current at half the voltage, especially since the power output is bound to be quadratic in
the drive current.

If the intermediate state is long-lived, that might not be so awful.

Fun, anyway!

Cheers

Phil Hobbs



--
Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

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On 20/10/2023 7:37 pm, Martin Brown wrote:

A breakthrough in low voltage blue LEDs announced recently this manages
to produce 2.7eV blue photons from an applied voltage of 1.47v! It is
the chemical equivalent of a Cockcroft-Walton voltage doubler.

https://www.sciencedaily.com/releases/2023/09/230920110657.htm

Or for more details the Nature paper (may be behind a paywall)

https://www.nature.com/articles/s41467-023-41208-7

It is a very cunning design and chemistry.

Damnit.

I was very pleased when I had found out that the marketing/design people
for a product that I designed had tried to swap out the LEDs from red to
blue in some misguided attempt to make the product look like a tacky
teenager's car with underbody lighting from the mid-2000s, and had been thwarted by the ~2.5V (IIRC) supply voltage of the microcontroller.

I shall have to prepare a new strategy to prevent anyone from defacing
my designs and impunging my dignity.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Chris Jones <lugnut808@spam.yahoo.com> wrote:

On 20/10/2023 7:37 pm, Martin Brown wrote:

A breakthrough in low voltage blue LEDs announced recently this manages
to produce 2.7eV blue photons from an applied voltage of 1.47v! It is
the chemical equivalent of a Cockcroft-Walton voltage doubler.

https://www.sciencedaily.com/releases/2023/09/230920110657.htm

Or for more details the Nature paper (may be behind a paywall)

https://www.nature.com/articles/s41467-023-41208-7

It is a very cunning design and chemistry.

Damnit.

I was very pleased when I had found out that the marketing/design people
for a product that I designed had tried to swap out the LEDs from red to
blue in some misguided attempt to make the product look like a tacky teenager's car with underbody lighting from the mid-2000s, and had been thwarted by the ~2.5V (IIRC) supply voltage of the microcontroller.

I shall have to prepare a new strategy to prevent anyone from defacing
my designs and impunging my dignity.

;)

Fortunately it only works for OLEDs.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

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On a sunny day (Fri, 20 Oct 2023 09:37:04 +0100) it happened Martin Brown <'''newspam'''@nonad.co.uk> wrote in <ugte7h$vajs$4@dont-email.me>:

A breakthrough in low voltage blue LEDs announced recently this manages
to produce 2.7eV blue photons from an applied voltage of 1.47v! It is
the chemical equivalent of a Cockcroft-Walton voltage doubler.

https://www.sciencedaily.com/releases/2023/09/230920110657.htm

Or for more details the Nature paper (may be behind a paywall)

https://www.nature.com/articles/s41467-023-41208-7

It is a very cunning design and chemistry.

One problem with OLEDs is burn in.
That goes for small ones as well as big ones for TV.
There was an article not so long ago about OLED TV burn in
https://arstechnica.com/gadgets/2023/10/not-burn-in-scary-oled-tv-image-retention-may-stem-from-buggy-feature/

I had to replace the OLED in my radiation meter / clock a year or so ago.
Now 10 year lifetime it had with always just numbers is not bad..

But for TVs it is a big issue.
There is talk about a class action lawsuit from some people against TV station's
logo burning in on OLED screens.
https://www.avforums.com/threads/should-tv-channels-be-held-responsible-for-logo-damage-on-oled.2261983/
There are thousands of complaints.

I have a nice Samsung LCD TV, now in use for maybe 10 years.

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On Fri, 20 Oct 2023 23:45:29 +1100, Chris Jones
<lugnut808@spam.yahoo.com> wrote:

On 20/10/2023 7:37 pm, Martin Brown wrote:

A breakthrough in low voltage blue LEDs announced recently this manages
to produce 2.7eV blue photons from an applied voltage of 1.47v! It is
the chemical equivalent of a Cockcroft-Walton voltage doubler.

https://www.sciencedaily.com/releases/2023/09/230920110657.htm

Or for more details the Nature paper (may be behind a paywall)

https://www.nature.com/articles/s41467-023-41208-7

It is a very cunning design and chemistry.

Damnit.

I was very pleased when I had found out that the marketing/design people
for a product that I designed had tried to swap out the LEDs from red to
blue in some misguided attempt to make the product look like a tacky >teenager's car with underbody lighting from the mid-2000s, and had been >thwarted by the ~2.5V (IIRC) supply voltage of the microcontroller.

I shall have to prepare a new strategy to prevent anyone from defacing
my designs and impunging my dignity.

In the pioneer days of Cree SiC blue LEDs, we used a blue LED as VME
module bus access indicator. It looked nice at 50 mA. As blue LEDs got
better, customers were whining about being blinded. I think we run
them around 1 mA now.

Blue can be annoying.

--- SoupGate-Win32 v1.05
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