Introduction

A light-emitting-diode (LED) is a semiconductor optoelectronic device, emitting a broad spectrum of light from visible through infrared. It is the fourth, most modern generation of light sources, already used in everyday life; following the flame, incandescent lamps and discharge lamps.

Historical Outline

The first known report about the invention of the light-emitting-diode dates back to 1907. It was developed and constructed by the British experimenter and inventor H. J. Round. In the 1920s, a Russian scientist – Oleg Vladimirovich Losev – made similar observations, completely independently. However, due to an almost complete lack of interest in the invention among the German and British scientific press, no practical use was made of the discovery for several decades.

In 1955 an American physicist – Rubin Braunstein – reported on infrared emission generated by simple diode structure using gallium arsenide (GaAs) semiconductor alloy. He also observed infrared emission generated by other alloys: GaSb, GaAs, InP or GeSi.

The first practical-visible-spectrum LED was developed by Nick Holonyak in 1962. This LED emitted red light. His student and follower – George Craford – developed the first yellow light emitting diode and a 10-times brighter red and red-amber diode.

 

Shuji Nakamura demonstrated the first blue LED

The invention has been developed in cooperation with a team of scientists in 1991. His blue LED emits the light with a luminous intensity of more than 1 candela. This development was based on gallium nitride (GaN) and was a milestone for the development of electroluminescent diodes. Later, in an interview for Science Watch in 2000, Shuji Nakamura said: „I actually thought it looked very easy to make blue LEDs, I thought blue means I just have to change the color. I just have to change the material.” The development of blue light emitting diode quickly led to the development of white LED.

LED structure

Theoretically a light-emitting-diode is a simple device. It consists of n-type semiconductor material, the active area (p-n junction), a layer of p-type semiconductor material and two leads connected to a p-type material anode and n-type material cathode.

In practice however the construction of a light-emitting-diode is based on the use of very advanced technologies. Thus, LEDs are often referred to as the 4th generation sources of light (following the flame, incandescent lamps and discharge lamps) or the light sources of the 21st century.

Advantages of LED Technology

• High light output – LEDs emit more light per watt than incandescent bulbs;
• LEDs can emit light of an intended colour without the use of any colour filters;
• LEDs can be designed to focus its light. Incandescent and fluorescent sources require an external reflector in order to obtain a similar effect;
• LEDs are ideal for use in applications that are subject to frequent on-off cycling. They are characterized by small inertia. Frequent on-off cycling does not result in increased energy consumption;
• LEDs achieve full brightness in a very short time. The majority of LEDs achieve full brightness in microseconds;
• Contrary to incandescent or fluorescent bulbs LEDs mostly fail by dimming over time. They don’t burn out abruptly in a split of a second;
• LEDs are characterized by a very long useful life, even 50 000 hours. Traditional bulbs are typically rated at about 1000-2000 hours;
• LEDs are very resistant to mechanical damages. Unlike fragile incandescent and fluorescent light bulbs they are difficult to damage with external shock;
• LEDs do not contain mercury;
• LEDs do not emit ultraviolet and infrared light.

Energy efficiency

LED light sources are an excellent replacement for traditional halogen lamps, which are commonly used to light show windows and all kinds of exhibitions. Their narrow stream of light can be precisely directed at the products which you want to draw attention to. Their high colour rendering index ensures that colours are reproduced naturally. In addition, light emitting diodes (LEDs) do not generate heat, which allows using them to light products which are sensitive to high temperatures.

Application

LEDs develop very dynamically. Laboratory investigations aimed at looking for electrical energy-saving products may lead to the conclusion that the near future is bound to bring a huge progress out. In the past LEDs were appropriate only for decorative and emphasizing lighting. Nowadays such light sources are used in main lighting as well. The advantages of such light sources cannot be underestimated, and among them: long lifetime, high colour rendering index and high luminous efficiency.

The era of quickly emerging new technologies creates a multitude of fields of application for LED-based lighting. Their high energy efficiency, which their most essential feature, motivates engineers to intensify their research on the use of LED sources in the lighting industry. Another driver for their development are the constantly rising costs of electricity, the increasing global power demand and the changes of climate caused by generation of energy. Another reason to favour LED sources are their light emitting characteristics, whose main advantage is the absence of ultraviolet and infrared wavelengths, as well as the fact that they do not contain mercury, an element present in compact fluorescent lamps harmful to environment.

LED lighting first entered our homes as part of all kinds of electrical equipment with built-in colourful light indicators. The negligible level of power consumption and the simplicity of operation of that kind of light source are the key drivers of its growing popularity.

Examples of LEDs used as indicator in electrical and electronic appliances:

• ActiveJet energy UPS unit with integrated LED indicators
• electronic equipment:
  
• car lights
  

Leading car manufacturers worldwide have started to implement modern LED lighting in their vehicles. Such solutions are most popular among the customers who require top notch design.

Our product range also includes premium brand car cosmetics, car service chemistry, car fragrances and liquid consumables and will soon be expanded by including car accessories.

HOME

Home is the place people care for most. One pays more and more attention to the quality of home lighting, its energy efficiency and harmony with nature. In order to address the expectations of our customers, we introduced LED light sources for the most widely used fixture types:

GU 5,3 (12V)	replacement for 30 Watt halogen lamp
GU 10 (~230V)	replacement for 30 Watt halogen lamp
E 14(~230V)	the popular "small threat" used in sconces, bedside table lamps
E 27 (~230V)	the most common home bulb fixture

PASSIVE HOUSE

In order to develop our energy efficiency concepts further, we took part in the first certified passive house project in Poland.

To see how much can be done to limit energy consumption, you can take part in ENERGY EFFICIENCY FAIRS or visit www.domy-pasywne.pl, the website on the Polish passive house project.

LED FLASHLIGHTS

The ActiveJet Energy product range includes 6 models of LED flashlights made of high quality aviation aluminium, a light and incredibly durable material. A system of special seals keeps moisture and dust away.

Ergonomic shapes and weather resistance of our flashlights make them extremely versatile and useful at home, in car, on trekking routes, etc. All models are shipped with a set of batteries included. Low power consumption ensures many hours of work, which means the flashlight will not run out of batteries when it is needed most.

LED STRIPS (SMD technology)

LED strips are used in visual advertising, as part of lighting of shop windows, furniture, bookshelves or decoration of interiors. LED strips can be used where the traditional light sources hardly fit in, such as in edges of frames, furniture parts, tile grouts or floors. They are perfect for creating long lines of light. Imagination is the only limit of how our products can be used.

Our LED strips are based on the most advanced SMD technology, which ensures their high luminous efficacy, durability and reliability.

We offer you products for indoor and outdoor use in a number of colours: warm and cold white, red, yellow, green, blue and RGB.

Using RGB diodes and a special controller, you are able to adjust the colour of light to your mood of the moment, which gives your home a unique atmosphere.

Indoor use

lighting of furniture, shelves, staircases, passageways

Outdoor use

• Home lighting, outdoor advertising
• Outdoor lighting, drive-over lighting, integrated LEDs

Garden lighting

Another interesting group of products are integrated LED fixtures: drive-over, wall or floor mounted and garden models. That kind of garden lighting creates an appealing visual effect. The drive-over fixtures are IP 67 certified and can be mounted in the pavement, with a durable tempered glass cover protecting them against tear and wear.

Using LED fixtures, you can keep your garden or driveway alight at all times without worrying about energy consumption costs.