YELLOW-GREEN 555-575mn

Spectrum of a typical "yucky" yellow-green LED courtesy of Kevin Gilmore and was used with permission.

Radio Shack # 276-304 Yellow-Green 5mm LED, $1.49 (for 2 pcs.)
Purchased 03-13-09, tested on 03-18-09
This is a yellow-green LED in a water-clear 5mm "through-hole" (round) epoxy package.

Beam photograph on the test target at ~12".

Same as above; different LED used.
Measures 850mcd on a Meterman LM631 (now Amprobe LM631A) light meter.

Vf is 2.052 volts at an If of 19.28mA.

Spectrographic plot
Spectrographic analysis of this LED.

Spectrographic plot
Same as above; different LED used.

Radio Shack # 276-0009 Bright Yellow-Green Rectangular LED, $1.79 (for two)
Purchased 02-19-09, tested on 02-21-09
This is a yellow-green LED in a water-clear rectangular epoxy package.

This is what the LED itself looks like.

Beam photograph at ~12".
The light is *VERY* dim; what you're seeing is mostly fading daylight here.

I do not yet have the target at my new Federal Way WA. USA location, so I shot this photograph onto the white wall just to the right of my "BIG SCARY LASER" poster (sent by

Measures 7mcd (yes, 7mcd!) on a Meterman LM631 (now Amprobe LM631A) light meter.

This is a very wide-angle LED; and if I've told you once, I've told you 2,458,770 times:
Wider viewing angles always, ALWAYS, ALWAYS equal lower mcd values!!!
Viewing angle is listed as 154.

Vf is 2.181 volts at an If of 19.28mA.

Spectrographic plot
Spectrographic analysis of this LED.
USB2000 Spectrometer graciously donated by P.L.

Manufacturer unknown, made for Radio Shack (Part # 276-304)
Purchased in mid-2004, tested 10-30-04
I came across a package of two of these yellow-green LEDs from Radio Shack while looking for a flashlight, so I might as well add it to this website. :-) This is a standard 5mm LED in a water-clear epoxy package. I don't know who makes the die (light-emitting chip) inside this LED, so please do not ask, thank you.
I believe this is a 565nm green/yellow-green LED.

Measures 1,501mcd at a drive current of 26mA and a Vf of 2.193 volts.
Light is considerably less yellowish/orangish than it appears in this photograph.

Manufacturer unknown
Received 07-03-04, tested 07-04-04
A fan of the website (J.R. in Michigan) sent 11 LEDs (thank you!!!), and one of these yellow-green LEDs were among the goods. This is a custom-moulded LED in a water-clear epoxy package. I don't know who makes the die (light-emitting chip) inside this LED, so please do not ask, thank you.
I believe this is a 555nm green/yellow-green LED. This appears greener and less yellowish than a typical yellow-green LED. The working chemistry is probably GaP (gallium phosphide).

I cannot obtain a beam photograph at the correct distance, so I photographed the LED itself next to a standard 5mm LED. This LED is the one closer to the bottom of the photograph, with the bends in its wire leads.

And here's a picture of its beam on the test target from approximately 4".
This LED appears to have an oval beam of 20-25 degrees by 30-35 degrees; since I do not have the equipment for measuring viewing angles, this is an eyeballed value. Brightness is too low for me to obtain a measurement using the equipment at my disposal.
Just by eyeballing things, it appears to be around 10-20mcd.

Unknown "double-green" LED, possibly dating to late 1970s, price/availability unknown (probably obsolete)
Here's an interesting animal that showed up meowing on my doorstep this morning (est. late 2000).
It appears to be an original "double-green" GaP yellow-green LED, housed in an elongated, oddly green tinted transparent case.
It just reeks of the 1970s - the last time I saw any LED like this was around 1978 or so; and I saw them come in both red and green.
The very elongated case, the long internal leadframe, the stoppers, even the odd green tint all remind me strongly of LEDs I haven't seen in a good twenty years.

double green LED double green LED
Close up of this unusual little LED. Doesn't it remind you of late 1970s technology?
Note the elongated case style and the unique double-bowl construction.

The LED is unusually dim for a double-chip model, probably cashing in at under 20mcd at full power.
Viewing angle is unusually wide for a transparent-case LED from this era, and appears to be around 50 to 60 degrees. Speaking of power, both chips are wired in series, and the LED requires at least 4.8 volts to light up well, and 5 volts to be reliable.

The color is a very yellowish shade of yellow-green, and appears to be a further indication of its age. (newer 565nm yellow-green models are noticeably less yellow).

Finally, although the case is considerably longer than most modern LEDs, the diameter appears to be standard T1 3/4 (5mm) and it should fit into openings designed for LEDs of that size.

AND183HPGP (probably Toshiba TLPGA183P), price/availability unknown
This GaAlAsP green LED is different than most others in this chemistry because of its color: it is a more "pure green" with less yellow coloration in it. Technically, the wavelength is around 550 to 555nm, versus around 565-570nm of other green or yellow-green LEDs using this chemistry. This makes it appear a deeper shade of green to your eyes.
Anybody who's owned a Commodore 64 with the 1702 monitor has probably seen one of these and not realised it. But if you've ever wondered why the indicator light in the monitor is a deeper green color than most other green indicator lights - this is one of those "pure green" LEDs.

UPDATE 04-18-00: A fan of the site has informed me that the "LED" in this monitor is actually a green neon lamp, driven off the monitor's flyback circuitry. It only looks like an LED because of the green rectangular lens and lack of 60Hz flicker.
Apparently, a friend of his dropped a 1702 and busted the tube, the neon bulb was discovered upon disassembly of the monitor's corpse.

The LED I'm testing today is a model AND183HPGP that a fan of the website sent me. It comes in a clear, T1 3/4 case, and has a fairly narrow beam I'd estimate to be around 15 degrees divergence. Although the LED isn't terribly bright, it focusses well and looks pretty bright when viewed straight on.

Use these where you want a noticeable bright green color, but don't need the extreme brightness or the expense of nitride-based green LEDs, and don't want the yellowish shade offered up by most other LEDs using this older chemistry.

Beam patternin color
Photographed in a dark environment, the somewhat weaker beam shows up better this way.

TLGE185EP (Hosfelt 25-366)
Here is a much brigher yellow-green LED than those I've seen up until now. Packaged up in a standard clear case, this LED is supposed to be rated at 3,500mcd, but it doesn't look quite that bright to me. It has a fairly narrow beam of 15 to 20 degrees with a darker area in the center, characteristic of many narrow-beam models. With that narrow beam though, this LED could easily be seen at fairly long distances.

An oddity with this LED, the one directly below, and to a lesser extent, the one directly above, is that when viewed from the side, the emitting surface of LED's die glows a yellow-orange color, turning all orange as the LED is turned more and more away from you. It doesn't seem to be an artifact caused by the LED's case, as it appears the same even under extreme magnification. The chip or die as it is called is opaque (it looks black) but the junction itself - the thin layer on top of the die that actually creates the light - could be transparent and tinted a brownish or amber color. This might cause the orange coloration of the light coming out of the junction's edges.

Also you may notice the chip is mounted up high and isn't recessed into the die cup that is usually used to collect and reflect otherwise wasted light. This is because the die is opaque and only emits from its upper surface - placing it deeper in the cup would not give any additional light - and seeing that the thin edges glow a different color, could actually taint the light coming from the LED's lens and cause it to become an ugly, irregular mixture of orange and green. There's definitely a method behind their madness. No defect here, they made them this way intentionally in order to ensure quality color output from piece ot piece.
One benefit to this configuration is that you don't get that ugly ring that is usually found outside the main beam of most narrow-beam LED models.

If these could be made with a transparent substrate, these could be some very bright LEDs indeed, ugly ring and all.

Beam patternin color
Beam from this bright yellow-green model.

TLGA183P (Hosfelt 25-341)
This LED appears virtually identical to the model directly above, but it has a narrower, more well-defined beam.
Rated at around 3,000mcd, this one seems to live up closer to its claim than the last one did.

The beam from this LED consists of a central "hot spot" of about 10 degrees or so, surrounded by a less intense corona of about another ten degrees.
Unlike many narrow-beam models, this one projects an even, round pattern that does not show the shape of its die, and as such would lend itself nicely for uses like keychain flashlights and model lighting. The beam photographs should tell the story here.

This LED also has the peculiar coloration when viewed from the side as the model above does, but it isn't quite as pronounced. The reason is the same, and I explained that in the LED review directly above this one.

Beam patternin color
Notice here the much narrower beam than what came out of the other yellow-green tested just above.

Radio Shack, part # 276-215, $2.39 10mm diffused green
This is one of those big jumbo 10mm LEDs, which, frankly, I don't know why were ever invented.
But they have, so here we go. This lamp produces a fairly bright light, as Gallium Aluminum Phosphide (GaAlP) models are concerned. Radio Shack had rated this one in the hundreds of mcd (somewhere between 200 and 600 if memory serves) but don't believe a word of it.
Far as I am able to determine, this one is in the 100mcd range - plenty bright to use as an indicator, but dim enough that it would become invisible in direct sunlight. In normal room light, this one produces a fairly well defined, somewhat narrow beam that falls off softly at its edges. The 10mm package is only partially diffused, so there isn't a terrible amount of waste light off to the sides.

These should work fine in a kid's project of some sort (traffic light?), but they would look kind of stupid mixed in with standard T1 3/4 sizes. Personal opinion, mind you. Your opinion and your results may vary.

Unknown, possibly Toshiba or Sharp, transparent green case
Here are some LEDs I cannibalized out of a pair of VCRs a number of years ago. Four samples were obtained from a Sharp model, and three out of a Toshiba.
All but one emit a very yellowish shade of green, with a wide, 40 to 45 degree beam. None are particularly bright, but served well as indicators behind transparent or transluscent buttons or panels. One of these has a much deeper green shade than the others; but has an identical physical appearance both externally and internally.

The lighter green models have a very wide spectrum, emitting light from deep red all the way to deep green. The deeper green model emits much less red, and possibly extends a few nm farther into the green region than the others. Because these aren't all that bright (I'd guess no more than around 5mcd each) the uses for these LEDs is probably limited to lighting switches & buttons, and backlighting thin silkscreened control panels.
One of these models also made an excellent replacement for the red LED in a voltage sniffer probe. So they're not useless, not by any means.

3mm (T1) size, transparent green tinted, manufacture unknown
This is a small, T1 (3mm) sized LED that was cannibalized out of a Christmas decoration quite a few years ago - so I have little real information to add.
It puts out a fairly ordinary, clear yellow-green light in a wide, 40 to 50 degree beam. Although this LED came out of a decoration originally, I could find a multitude of other everyday uses for it; from panel indicators, model sets, even in nightlights for baby's room. Call it a "general purpose" model if you will.

WHITE 5500-6500K InGaN+phosphor 
ULTRAVIOLET 370-390nm GaN 
BLUE 430nm GaN+SiC
BLUE 450 and 473nm InGaN
BLUE Silicon Carbide
TURQUOISE 495-505nm InGaN
GREEN 525nm InGaN 
YELLOW-GREEN 555-575mn GaAsP & related
YELLOW 585-595nm
AMBER 595-605nm
ORANGE 605-620nm
ORANGISH-RED 620-635nm
RED 640-700nm
INFRARED 700-1300nm
True RGB Full Color LED
Spider (Pirrahna) LEDs
True violet (400-418nm) LEDs
Agilent Barracuda & Prometheus LEDs
Oddball & Miscellaneous LEDs
Programmable RGB LED modules / fixtures
Where to buy these LEDs 
Links to other LED-related websites
The World's First Virtual LED Museum
The Punishment Zone - Where Flashlights Go to Die
Legal horse puckey, etc.
LEDSaurus (on-site LED Mini Mart)

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