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Light Emitting Diode

After removing the cover of the phone, and examining the circuit board, we decided to examine one of the components in more detail. We first chose one of the Light Emitting Diodes. These were primarily used to light up the key pad when pressed, and light up when a call is being recieved.

We first removed one of the LEDs from the circuit board, and placed on a new circuit board so we can examine it more easily.

Light Emitting Diode

The LED under an Optical Microscope.

To check that the LED still worked, we placed it under the optical microscope, and passed various voltages across it, to see if would light up, and still behave how an LED should. Below are the photos taken at various voltages.

 LED with 0 volts LED with 2 volts LED with 4 volts 

0 Volts 2 Volts 4 Volts

 6v.jpg LED with 8 volts 

6 Volts 8 Volts

Here we can see the LED behaving as we would expect, with noticeable amounts of light being given off once around 3 volts are passed across the LED.

We then placed the LED in the Scanning Electron Microscope, to examine in more detail and try to identify which elements it was made of.