Until recently, LEDs were too expensive to use for most lighting applications because they’re built around advanced semiconductor material. The price of semiconductor devices plummeted after the year 2000, however, making LEDs a more cost-effective lighting option for a wide range of situations. While they may be more expensive than incandescent lights up front (about $5 versus $1 for incandescent bulbs), their lower cost in the long run can make them a better buy. Several companies have begun selling LED light bulbs designed to compete with incandescent and compact fluorescents that promise to deliver long lives of bright light and amazing energy efficiency.
In this article, we’ll examine the technology behind these ubiquitous blinkers, illuminating some cool principles of electricity and light in the process.