Essay On Gallium Based LED

To the untrained eye, the two elements are often interchangeable in terms of color and

Then they return to their ground state by emitting a photon of light. The amount of energy in the photon determines its colour.

Semiconductor Nano crystals or quantum dots are materials that are typically 2-20 nm in diameter, consisting of approximately twelve to fourteen thousand atoms. The effect of quantum confinement results, in the electrons and holes in the Nano crystal to exhibit quantized energy states; thus enabling them to exhibit novel physical properties that are not found in their bulk counterparts. Research in semiconductor quantum dots started with the realization that the optical and electronic properties of these particles were strongly dependent on particle size, due to quantum confinement of the charge carriers in small spaces.

The authors are S. H. Abo El-Nor, H. M. Khattab,  S. M. Khalif, H. M. El-Sayed, O.H.

The light emitting diodes (LEDs) are low energy, lighting devices with a long lifespan and low energy consumption. The LEDs use specialized power

Goal: Synthesize Cadmium Selenide (CdSe) Quantum Dot Crystals using Cadmium Oxide (CdO) and Selenium (Se) dissolved in Triphenylphosphine solution. The product created will be a colloidal solution, bound to the exterior of the crystal lattice and it remains soluble in the octadecene (Boatman & Nordell). Along with this the product will most likely vary in color as well due to the changes in wavelength, energy and transitions, that all correspond to a smaller crystal. The variations in particle size will prove to be an important feature in the experiment, so the goal is to use diverse size particles. The crystals are created in a solution in which they cannot be filtered out since they do not settle.

Light can be produced in many different ways, including incandescence, phosphorescence, and fluorescence (Gunderman 1). Incandescence is when heat makes an object release light, like the filament in a light bulb. Phosphorescence is when a material absorbs energy and then releases it slowly over time, like glow-in-the-dark toys. Fluorescence is when a material absorbs energy and releases it quickly as light (Gunderman 1). Fluorescence is the process used in glow sticks (Science Fair Projects 1). The fluorescent dye in this experiment’s glow sticks released yellow light. Different color glow sticks are made with different dyes (Harris 2).

This occurs when a product is generated in the excited state and then relaxes to the ground state in which a photon is emitted. When the electron relaxes, energy is released as a vibration and heat. Electrons in the same orbital are paired and must have opposite spins. There are two types of electronic states: singlet and triplet. In a singlet state, the spins of all of the electrons are paired while in a triplet state, the spins are flipped or unpaired. Phosphorescence and fluorescence occurs when electrons relax from the singlet and triplet states and emit visible light. Fluorescence emits light at a longer wavelength than it is absorbed. This process is rather fast as the light appears to be a blue-green color. Phosphorescence is very similar to that of fluorescence. However, in phosphorescence there is longer interval between the excited and ground states since the flipped spin has to flip back. This flipping of spins requires energy which leads to a less energetic triplet state compared to that of the singlet state. The longer interval in phosphorescence also sometimes results in a red color and a longer excited state period. Chemiluminescence also has other usages such as its ability to identify when blood is present. The luminol turns blue-green when the alkaline solution is exposed to

When white light (which is made of all the colors of the rainbow) strikes a red object, its atoms specifically absorb and re-emit red light; all the other colors of light simply cause the object to get a bit warmer. At the point when a fire works blast, it conveys smoldering protuberances that contain, in addition to other things, metal salts. These metal salts are warmed and start sparkle in fabulous hues. Metal salts that are regularly utilized as a part of fireworks presentations include: strontium carbonate (red fireworks), calcium chloride (orange fireworks), sodium nitrate (yellow fireworks), barium chloride (green fireworks) and copper chloride (blue fireworks).

Why does the synthetic material CD produce a different looking representation of color than the prism

If you want to take benefit of quality light bars better than standard ones, using the LED light bars are the right choices for you at the right time. According to

LED’s are different to standard lighting: They don’t really burn out and stop working like a standard light, moreover the lighting diodes emit lower output levels over a very long period of time and become less bright.

This study is beneficial to people who live in places that have extreme temperature changes. The conclusion of this experiment will provide people who live in climate changing places with the right answer, whether or not purchasing a different colored LED light is beneficial or not. With the knowledge of which color LED lights perform the best these people can purchase the most reliable flashlights in case of an emergency. For instance, let's say that there is a power outage during a storm and someone cannot come to fix your air conditioner and you live in a hot environment. Knowing if the colored LED flashlight or the clear LED flashlight performs better in the heat can help. LED flashlights performs just like humans, when we get hot we get tired. Therefore it is nice to know which light will keep the same output after being on for a long period of time.

Cree has initiated a new kind of LED streetlights with warmer lighting. This new streetlights was developed according to the requirement from residents of Raleigh’s older neighborhoods.

The purpose of this paper is to give a greater understanding of the semiconductor world, for Physics 100 students who have a little knowledge of electronics. I will cover conductors, insulators, semiconductors, and the operation of a diode and a transistor. The reason that it is important to understand these devices is the vast effect that they have had on our modern world. Our lives are filled by electronics, especially in this computerized age that we live in, and I have found that a knowledge of some electronics has greatly helped my understanding of the many electronic devices that we deal with on a daily basis.