The Future of Lighting: LEDs and OLEDs

Incandescent bulbs have been around for over a century, but light-emitting diodes (LEDs) have – in recent times - replaced them in the popularity sweepstakes. Many countries backing energy efficiency are opting for LEDs despite their high initial costs.

How did the big switch happen? The first LED was developed in 1962, and, since then, the lighting solutions have come a long way. Once available only in red, LEDs are now available in colours galore and have become extremely popular across the world. Their use is seen in numeric displays and indicator lights and in a variety of new applications such as accent lights, task lights, wall sconces, signage, traffic lights, cove lighting, down-lighting, outdoor lighting and exit signs. 

What exactly is an LED? The diodes are solid-state semiconductor devices, which achieve illumination when a semiconductor crystal is excited – it then directly produces visible light in a desired wavelength range (colour). LED units are small, typically 5mm. LED lighting systems are extremely flexible. A single lighting system can create an almost infinite number of effects, moods and ambiances – be it in retail spaces, offices, hospitality structures or outdoors. LEDs also offer immense design flexibility in color changing, dimming and distribution – the small-sized units can be easily combined into a combination of shapes, colours, sizes and lumen packages.

LEDs offer a host of advantages when compared to conventional lighting units - long lamp life, low heat output, small size, durability and energy savings are a given. As LEDs consume only about 20 per cent of the energy used by incandescents, and as almost 20 per cent of the world's electricity is used for lighting, opting for LEDs will greatly reduce energy costs and greenhouse gas emissions.

LEDs, however, are not the end of the road for lighting. Experts predict that organic light-emitting diodes (OLEDs) may be the next big thing on the lighting market and may replace LEDs as the most energy-efficient alternative to conventional lighting. 

OLEDs (Organic Light Emitting Diode) are millimeter-thin glass wafers with organic materials enclosed in them. These form layers which are around 400 nanometers thin, which the current can flow through. The organic layers are enclosed by an anode and a cathode layer, which function as the electrical contacts from both sides. The organic layer contains molecules which begin to glow when an electric current passes through them. The particular molecular structure determines the colour of the light. The organic layers are coated to protect them from external effects.

OLEDs are likely to change our very perception of lighting and architecture. Once the use of OLEDs is widespread, the architectural elements themselves could be used as lighting hardware – sheets can be cut and used as lighting wallpaper!