Optoelectronics and Light Emitters

A light-emitting diode (LED) is a semiconductor device that emits light when an electric current passes through it. It's essentially a diode that releases energy as photons, creating visible light.

When an LED is forward-biased, electrons from the n-type material recombine with holes in the p-type material. This recombination releases energy in the form of photons, which we perceive as light.

The color of light emitted by an LED is determined by the energy gap of the semiconductor material used. Different materials have different band gaps, leading to different wavelengths of light.

Electroluminescence is the phenomenon where light is emitted when an electric current passes through a material. LEDs are a prime example of electroluminescence.

LEDs offer several advantages, including lower energy consumption, longer lifespan, improved robustness, smaller size, faster switching, and greater durability and reliability.

LEDs are categorized based on their wavelength, which depends on the semiconductor material used. They can be classified as visible, ultraviolet, and infrared LEDs.

The power of light output in an LED is directly proportional to the forward current. A higher current produces brighter light.

LEDs have a lower reverse breakdown voltage compared to silicon rectifier diodes, typically ranging from 3 to 10 volts.

A graph showing the intensity of light emitted by an LED at different wavelengths. It helps determine the color and brightness of the LED.

The voltage difference across an LED when it is forward-biased and conducting current. It varies depending on the LED type, color, and current.

A diagram showing the distribution of light emitted by an LED in different directions. It helps understand how the light is concentrated and spread.

The amount of power consumed by an LED as it converts electricity into light. It's calculated by multiplying forward voltage and current.

A display made of seven individual LEDs arranged in a specific pattern to represent numbers and characters. Each segment can be turned on or off individually.

A type of LED that emits infrared light, which is invisible to the human eye. Commonly used in remote controls.

A resistor connected in series with an LED to limit the current flowing through it. It protects the LED from damage due to excessive current.

Using an LED as a simple visual signal or indicator, often to show the status of a device or system.