Discussion in 'Economy & Infrastructure' started by Raj30, Jul 23, 2012.
LED Industry: China leaps as India sleeps - Moneylife Personal Finance site and magazine
so what is the solution? he suggests nothing. would a LED policy be helpful in this regard? and wouldn't these LED's with embedded chips be susceptible to EMP attacks?
Crouching Tiger, Hidden Dragon (Wo hu cang long)
Possible steps to undo the damage already done:
1) Promote the set up of polysilicon wafer fabs, announce tax holidays for atleast 10 to 20 years. Set up large townships, replete with assured 24*7 power , water and good quality world class roads. These should be supplemented with world class ports, for quick and efficient outgoing shipment of finished merchandise.
2) Be ready to dish out big money, and create an investor friendly climate, with low corruption, and quick addresal of applications.
The fact is LED is just one part of the high capital, high tech, business of electronic products. India can be a part of world if she is ready to put her money where her mouth is. Polysilicon wafer is the the heart and soul of the electronic industry. And setting up plants of polysilicon wafer is obscenely expensive to say the least. A standard plant manufacturing LED would need an investment of alteast 800 to an 1000 crore rupees. And that does not include the polysilicon foundry!To offer some perspective, a fab of the caliber of Intel or AMD would require an investment of ateast 1 to 2 billion dollars.There a handful of countries manufacturing polysilicon, and among them making for microchips are even more high tech. India does not have foundrys even for something as low tech as solar panels, where all the polysilicon ingots are imported from taiwan.
India missed the microelectronics bus in the early 1970's. We can be back in the game, but that would require big money and big efforts.
Show bill, buy LEDs at half price from tomorrow - Times Of India
Physics of LED:
The LED consists of a chip of semiconducting material doped with impurities to create a p-n junction. As in other diodes, current flows easily from the p-side, or anode, to the n-side, or cathode, but not in the reverse direction. Charge-carriersâ€”electrons and holesâ€”flow into the junction from electrodes with different voltages. When an electron meets a hole, it falls into a lower energy level, and releases energy in the form of a photon.
The wavelength of the light emitted, and thus its color depends on the band gap energy of the materials forming the p-n junction. In silicon or germanium diodes, the electrons and holes recombine by a non-radiative transition, which produces no optical emission, because these are indirect band gap materials. The materials used for the LED have a direct band gap with energies corresponding to near-infrared, visible, or near-ultraviolet light.
LED development began with infrared and red devices made with gallium arsenide. Advances in materials science have enabled making devices with ever-shorter wavelengths, emitting light in a variety of colors.
LEDs are usually built on an n-type substrate, with an electrode attached to the p-type layer deposited on its surface. P-type substrates, while less common, occur as well. Many commercial LEDs, especially GaN/InGaN, also use sapphire substrate.
Most materials used for LED production have very high refractive indices. This means that much light will be reflected back into the material at the material/air surface interface. Thus, light extraction in LEDs is an important aspect of LED production, subject to much research and development.
Bare uncoated semiconductors such as silicon exhibit a very high refractive index relative to open air, which prevents passage of photons at sharp angles relative to the air-contacting surface of the semiconductor. This property affects both the light-emission efficiency of LEDs as well as the light-absorption efficiency of photovoltaic cells. The refractive index of silicon is 3.96 (590 nm), while air is 1.0002926.
In general, a flat-surface uncoated LED semiconductor chip will emit light only perpendicular to the semiconductor's surface, and a few degrees to the side, in a cone shape referred to as the light cone, cone of light, or the escape cone. The maximum angle of incidence is referred to as the critical angle. When this angle is exceeded, photons no longer penetrate the semiconductor but are instead reflected both internally inside the semiconductor crystal and externally off the surface of the crystal as if it were a mirror.
Internal reflections can escape through other crystalline faces, if the incidence angle is low enough and the crystal is sufficiently transparent to not re-absorb the photon emission. But for a simple square LED with 90-degree angled surfaces on all sides, the faces all act as equal angle mirrors. In this case the light can not escape and is lost as waste heat in the crystal.
A convoluted chip surface with angled facets similar to a jewel or fresnel lens can increase light output by allowing light to be emitted perpendicular to the chip surface while far to the sides of the photon emission point.
The ideal shape of a semiconductor with maximum light output would be a microsphere with the photon emission occurring at the exact center, with electrodes penetrating to the center to contact at the emission point. All light rays emanating from the center would be perpendicular to the entire surface of the sphere, resulting in no internal reflections. A hemispherical semiconductor would also work, with the flat back-surface serving as a mirror to back-scattered photons.
India can manufacture limited quantities of Gallium Arsenide, which is used in the radar programmes, has most possibly set up a fab, but I do not know about the foundry. They are possibly trying to create plants for GaN too, I doubt if their technology can be scaled up to meet commercial demands. But the even more pertinent doubt is if the miserly Indian business establishment be ready to shell out really big cash in a field where return is not assured?
If there is half chance of this happening in India it would be only because of Narendra Modi. Though I am not a big fan of personality cults but sadly there are not many choices.
This is a lame-duck article. What for? That China has a huge leg up on India in terms of manufacuring capabilities, is an established fact. Neither is the LED industry the only kind manufacuring where China has a huge presence internationally and India has none of it. Why not lament about shipbuilding, precision-machinery, solar panel, consumer electronics, construction materials, etc, etc. The author could even lament on why Boeing and Airbus dominate the sky while India can't even produce the smallest passenger plane.
You don't need to scratch the head for an answer because the answer is already there: that's the way it is.
Not only LED but also in semi conductores and microprocessers china is years ahead of us
^ You like LED lights Fo Real ?!? I like LED lights too ! LED lights i use in ma car ma bike ma kitchen, hell, even in ma toilet Yo ! LED lights saves teh day
What's really puzzling is why the author keeps harping on 'China does this' as a justification for India to do something, rather than a more straightforward argument that the LED industry can bring much-needed high-skill manufacturing jobs to India...
Because putting the word "China" into his article would bring far more attentions from readers.
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