The LED green divide effective solution to the new material

( Reading] The university of Cambridge, 剑桥大学) With 2 semiconductor companies have cooperation with cubic gallium nitride ( 立方氮化镓; Or 3 c GaN) Materials, as a green light LED materials, hope to be able to solve. 。 。

the university of Cambridge, 剑桥大学) With 2 semiconductor companies have cooperation with cubic gallium nitride ( 立方氮化镓; Or 3 c GaN) Materials, as a green light LED materials, hope to be able to solve the green part of the material appears green gap due to poor conversion efficiency ( greengap) The problem.

Electronics Weekly web site reported that the cooperation with university of Cambridge, total Plessey Semi semiconductor company and Anvil Semi 2 semiconductor companies, etc.

the Plessey manager DaveWallis, traditional 6 GaN, electric field will show up in the crystal face (c c - 飞机) , is conducive to make transistors, but when manufacturing the LED will be separate form the photon electron and hole, and thus formed the so-called history of tank effect ( 量子限制斯塔克效应) 。 And once the indium ( 铟) Quantity is increased, the effect will be intensified, but due to the mechanism of indium is added to spin GaN LED wavelengths, in other words, the effect has become a green light GaN LED the main impediment to effective emission.

however, Wallis, points out that if the substitution of cubic GaN symmetry will change due to its electric field will disappear, let this effect cannot continue to hinder the photons. Whether this effect is caused by green divide the only culprit has not determined, but using cubic GaN green light LED to internal and external quantum efficiency is better, each unit of electronic also can form more photons.

Wallis also pointed out that using cubic GaN another benefit is the green LED energy gap is lower than six edge GaN 200 mv, so can save the use of indium, but also has its disadvantages. Because in GaN, 3 c crystal lattice on thermodynamics is unstable, so, can the temperature of the growth of epitaxial, only six edge crystal can form, unless the energy balance can be adjusted through the artificial to, fortunately, Anvil semiconductor has developed methods. Using the company invented the growth of the cubic silicon carbide ( 立方碳化硅) Method, the lattice constant is very close to what cubic GaN, cubic crystal can grow smoothly.

Wallis, Cambridge university has been successful to grow less than 99% of GaN cubic structure and growth quantum well on material, the school will continue to grow up in quantum well near future N and P type layer, so as to form through bias converts electronic photon diode.

comments pointed out that the Anvil process another advantage, which is on the low cost silicon wafer growth cubic silicon carbide, and the university of Cambridge known as wafer growth six edge GaN technology also have been sold to Plessey, the latter has begun to use on the blue and white LED. Future wait for N and P type after integration in Cambridge university, wafer will be sent to the Plessey workshop and start deposition electrode, in order to form the green leds can run. At present three party cooperation has entered the 3 months, is expected to produce green in September 2016 cubic GaN leds.

as to how the luminous efficiency, Wallis expectations can efficiency of green and blue light. And he points out, as a result of this union with 6 inch wafer, therefore, will produce using 150 mm green LED process.