Led working and basic......

LIGHT EMITTING DIODE

PRAFUL T. SONAWANE

LED SYMBOL

CATHODEANODE

LED WORKING PRINCIPLEBASICHOW IT WORKS

BASIC BASIC• BASICALLY LED(LIGHT EMITTING DIODE) CONSIST OF TWO LAYER.• ONE IS OF ‘P’ TYPE MATERIAL AND SECOND IS OF ‘N’ TYPE MATERIAL.• THERE IS JUNCTION WHICH CONNECTED THIS TWO LAYER.

‘P’ TYPE LAYER

‘P’ TYPE LAYER IS FORMED WHEN WE DOPED SILICON WITH A MATERIAL HAVING VALENCE ELECTRON LESS THAN THAT OF THE VALENCE ELCTRON OF SILICON OR LESS THAN FOUR.DUE TO ACCESS OF HOLES(POSITIVE CHARGE) THEY ALWAYS ATTRACT NEGATIVE CHARGE ELECTRON.

‘N’ TYPE LAYER

‘N’ TYPE LAYER IS FORMED WHEN WE DOPED SILICON MATERIAL WITH THE MATERIAL HAVING VALENCE ELCTRON IS GREATER THAN THAT OF THE SILICON VALENCE ELCTRON OR GREATER THAN FOUR.

DUE TO ACCESS OF ELCTRON THEY ALWAYS ATTRACT HOLES OR POSITIVE CHARGE.

‘P’ TYPE MATERIAL ‘N’ TYPE MATERIAL

IN THE LEFT SIDE THERE IS ‘P’ TYPE LAYER.

IN THE RIGHT SIDE THERE IS ‘N’ TYPE LAYER.

IN THE MIDDLE OF ‘P’ TYPE AND ‘N’ TYPE THERE IS JUNCTION..

WHEN CIRCUIT IS ON : DUE TO POSITIVE-POSITIVE CHARGE

INTERACTION AT THE LEFT SIDE THE HOLES ARE PUSHES TOWARDS JUNCTION.

ON THE ANOTHER SIDE DUE TO NEGATIVE-NEGATIVE CHARGE INTERACTION AT THE RIGHT SIDE THE ELCTRON ARE PUSHES TOWARDS JUNCTION.

IN THE HEART OF THE JUNCTION BOTH ELECTORN AND HOLES ARE MERGE AND LIGHT PHOTON FORM.THIS IS HOW LED WORKS.

THANK YOU

PRAFUL T. SONAWANE