Everyone is familiar with the LED (Light Emitting Diode), but I recently saw a reference to a Light Emitting TRIODE. LET Does such a thing exist? I could not find anything useful with google. If it does, what does it do that a LED cant?
** Google is chock full of papers and tech info on the device.
You blind ??
... Phil
The old-fashioned tv/monitor tube.
The "cats eye" tuning light on old radio's.
The ringcounter display tubes in counters.
The plasma Tv tube, contains about 600.000 of them, each pixel a small emitting tube.
It's supposed to be a 2006 improvement on LED technology.
This paper pops up from several sources:
Journal of The Electrochemical Society, 153 8 G734-G737 2006
0013-4651/2006/153 8 /G734/4/$20.00 (c) The Electrochemical SocietyGaN Light-Emitting Triodes for High-Efficiency Hole Injection
Jong Kyu Kim,a E. Fred Schubert,a,*,z Jaehee Cho,b Cheolsoo Sone,b J. Y. Lin,c H. X. Jiang,c and J. M. Zavadad
aDepartment of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA bPhotonics Program Team, Samsung Advanced Institute of Technology, Suwon 440-600, South Korea cDepartment of Physics, Kansas State University, Manhattan, Kansas
66506, USA dU.S. Army Research Office, Research Triangle Park, North Carolina 27709, USA A new type of light-emitting device, the light-emitting triode LET is demonstrated to have enhanced hole-injection efficiency. The LET has an additional anode to accelerate carriers in the lateral direction by means of an electric field between the two anodes. Theoretical calculations reveal that the lateral electric field provides additional energy to carriers, thereby allowing them to overcome barriers and increasing the carrier injection efficiency into the active region. It is experimentally shown that the light-output power of the LET increases with increasing negative bias to the additional anode, which is fully consistent with the expectation. (c) 2006 The Electrochemical Society. DOI: 10.1149/1.2204873 All rights reserved. Manuscript received January 16, 2006. Available electronically June 5, 2006.AlGaN-based ultraviolet UV light-emitting diodes LEDs are attracting much attention for applications such as chemical and biological detection systems, water and air sterilization, and as a primary light source for phosphor-based white LEDs.1-3 Although UV LEDs are already commercially available, highly efficient UV LEDs are still difficult to fabricate. Improvement of the efficiency is one of the most important challenges especially for deep UV LEDs 340 nm which have very low internal quantum efficiency. In AlGaN-based UV LEDs, an electron-blocking layer EBL is frequently inserted between the p-type cladding layer and the active region. The EBL has the purpose of preventing electron overflow from the active region, and hence, confining electrons to the active region. Figure 1a shows a schematic band diagram of a UV LED with an EBL on a multiple quantum well MQW active region. The EBL does not impede hole injection into the active region, if the EBL is heavily p-doped. However, AlGaN with high Al content generally lacks high p-type doping capability which is caused by the high acceptor activation energy of 200 meV. If the EBL is undoped or low p-doped, it will not only block electrons from escaping the active region but also hinder the injection of holes into the active region by the potential barrier, as shown in the Fig. 1a. The tunneling probability of holes through the EBL is low due to a high potential barrier as well as the heavy mass of holes in GaN mh * = 0.80 me and AlN mh * = 3.53 me . This limits the hole injection efficiency into the active region, and hence internal quantum efficiency. To overcome the lack of p-type conductivity in bulk films, Mg doped AlxGa1-xN/GaN superlattices SLs have been proposed and demonstrated to have a doping efficiency that is 10 times higher than that of bulk p-type GaN.4,5 The enhancement of carrier transport has been verified in lateral direction, i.e., parallel to the SLs planes. However, carrier transport along the perpendicular direction through p-n junction, which is required in typical light-emitting devices, is less efficient than along the lateral direction because most of the holes ionized from the acceptors are localized inside the quantum wells which are clad by potential barriers as high as 100 to
400 meV.6 The hindrance of carriers in overcoming the barrier results in a low injection efficiency of carriers in the active region, leading to poor internal quantum efficiency of LEDs. Figure 1b shows a schematic band diagram of an LED with p-type SLs on top of the MQW active region. A schematic description of electron and hole transport in the LED structure is also shown. Efficient injection of holes into the active region of a LED is required for high radiative efficiency. For inefficient hole injection into the active region, electrons will diffuse through the active region into the p-type confinement layer, where nonradiative recombination is likely. The light-emitting triode LET has been motivated by the problem of low injection efficiency in LEDs having a p-type superlattice in the confinement region.7-9 Schematic sketches of the LED and LET are shown in Fig. 2a and b, respectively. Radiative recombination in active region is strongly required for high-efficiency lightemitting devices. In LEDs, however, nonradiative recombination occurs in p-type confinement region due to an inefficient hole injection over the potential barrier, either by EBL or SLs. The LET is similar to a conventional LED with one important difference: The LET has three terminals, two of which are p-type terminals, anode 1 and anode 2, and one of which is an n-type terminal, cathode, as shown in Fig. 2b. The fundamental operating principle of the LET is as follows. We assume that the cathode is grounded and the two anodes are both biased at a different level. As a result, a current will flow laterally from one anode to the other anode. In the process, the holes will be accelerated, gain a higher energy, and, hence, be able to overcome the potential barrier by either EBL or SLs and be injected into the active region more easily as compared to a device with one anode. Thus, the LET structure is a promising new structure with potential advantages for devices that have SLs in the p-type confinement region as well as for UV devices that have an EBL. [ Please see rest of paper. There is much more. ]
Don't you mean:
"light emitting transistor"?:
November 1, 2006 , Light-emitting transistor uses light to transfer an electrical signal:
Jun 15, 2009, Light-emitting transistor sets record:
Then by internally connecting the base and collector of a light- emitting transistor, they also created a new form of light-emitting diode, which modulates up to 7 gigahertz -- breaking the speed record once again. ..."
29 JUN 2010, A Color-Tuneable Organic Light-Emitting Transistor:Nov. 29, 2004, New Transistor Laser Could Lead To Faster Signal Processing:
Apr. 10, 2006, Hidden Structure Revealed In Characteristics Of Transistor Laser:
May 17, 2010, Redefining Electrical Current Law With the Transistor Laser:
The unique properties of the transistor laser required Holonyak, Feng and graduate student Han Wui Then to re-examine and modify the law to account for photon particles as well as electrons, effectively expanding it from a current law to a current-energy law. ..."
-Please note that the electrodeless lamp has been invented:
Nov 1, 2002, EC&M: RF Lighting Tunes in Improved Illumination:
Electrodeless Induction Lamps :
Illumination:
Glenn, The information you posted mostly went in the direction of higher speed data transmission, but the Jong Kyu Kim et alia paper went in the direction of efficiency and higher brightness.
Both are noble goals, just specialized in different directions.
I kept thinking the Kim et alia paper was about light junctions for brighter Video monitors even though they mentioned some other industrial purposes.
One of the references you posted mentioned changing color so at least one of those could also end up changing video technology.
There must be a lot of big money and a huge ROI in obtaining tighter video resolution, more brightness and more color depth.... Right?
Magic Eye toob
Cheers
VFD - Vacuum Fluorescent Display.
Each segment is a triode: (part of) the filament (part of) a grid one anode (the part that lights up)
Arie de Muynck
If you supply enough voltage and current, almost almost any triode will emit light, for a short period of time. ;-D
Cheers! Rich
On a sunny day (Mon, 27 Dec 2010 10:43:45 -0800) it happened Rich Grise wrote in :
All tube triodes emit light from the heaters.
-- http://www.scientific.net/MSF.663-665.791
On a sunny day (Mon, 27 Dec 2010 13:15:46 -0600) it happened John Fields wrote in :
Yes, true, but did you know you cannot buy those field emission displays anywhere? I think it is just an other 'nano nano' invention, that works in the lab, but has too many practical problems to be used. Maybe it just sucks electrons from that so called 'cathode'. That would also happen if you bring the anode close enough (contact). They may even invent the field effect transistor LOL.
Too many tissue papers leading to dead end roads.
A very big manufacturer gave up on it and sold the patents to some other big one, who probably will fail too. Good chance if you sneeze next to such a display with the electrodes so close, you permanently damage those 'points'. We used to call that 'arcing' in the last century.
Crap.
anywhere?
-- What difference does that make? The point wasn't whether field emission displays are commercially available, it was that there are _some_ triode tubes that, having no heaters, _don't_ emit light from their heaters.
On a sunny day (Mon, 27 Dec 2010 13:56:14 -0600) it happened John Fields wrote in :
Would not be a bad idea in some cases.
Plod along much, as you stumble through life on the coattails of those who know?
Backlighting is white. The LCD panel does the coloration. Applying colorations to portions of the backlighting plane would only complicate input requisites. OLED was a start on a panel that requires no backlighting. THAT will be the direction we move toward. Not OLED per se, but directly illuminated pixels with no backlight requisite ala OLED will be. The only problem OLED has is longevity or it would already be mainstream.
I'd love to know what pixel sizes they are working with so far are.
Can you post the reference? It may be nothing more than a dual red/green LED that some marketing/advertising weenie got creative with and called a LET. Art
You've been had! ;0
Triode as you most likely already know is a 3 element tube.
I could be wrong how ever, history tells me that it's latin for 3 what ever.
I don't think a "triode" tube could be exclusive in it's use!
But then again, I could be wrong! ;)
I am sure Sloman will confirm that !
Jamie
How about another example of a non-light-emitting triode? Vacuum tubes made with metal "bottles" rather than glass ones!
Such as 6SN7 dual triode, where the glass bottle version is 6SN7GT ("glass tube") IIRC. Unless one wants to argue on basis that the light is emitted after all while not escaping the electronic component where it was generated.
-- - Don Klipstein (don@misty.com)
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