Presented by :

Avinash Kumar Tiwari

B.Tech.(MAE)

Amity University

Jharkhand

SOLAR CELL

TECHNOLOGY

• INTRODUCTION

• HOW IT IS MADE ?

• WORKING PRINCIPLE

• APPLICATIONS

OVERVIEW

• A SOLAR CELL is a solid state electrical device that

converts energy of light directly into electricity by

Photoelectric Effect.

• A SOLAR CELL is also known as Photovoltaic Cell or

Photoelectric Cell.

INTRO TO SOLAR CELL...

• Solar Panels are made up off small units called solar

cells.

• A single cell can produce only very tiny amounts of

electricity

• It can be used only to light up a small light bulb or

power a calculator.

• The most common solar cells are made from SILICON (a

semiconductor that is the 2’nd most abundant element

on earth).

HOW IT IS MADE ??

• In a solar cell crystalline Silicon is sandwiched between

conductive layers.

• A N-type Silicon has majority of electrons.

• A P-type Silicon has majority of holes.

• When a P-type and a N-type Silicon comes in contact ,by the

combination of electrons and holes a layer is created at p-n

junction called as DEPLETION LAYER.

• STEP 1: When a P-type and a N-type semiconductor come

together they form a p-n junction.

• STEP 2: Electrons wander across the junction, leaving behind

static positive charges on atoms. On the other side ,they join

up with holes causing both to disappear.

WORKING PRINCIPLE

• STEP 3: At the same time, holes wander across the junction,

leaving behind static negative charges on atom. On the other

side, they join up with electrons causing both to disappear.

• STEP 4: The separated static positive and negative charges

produce an electric field across the depletion zone.

• STEP 5: When light energy is absorbed by the

semiconductor ,it will dislodge an electron , creating an

extra mobile electron and an extra mobile hole. This is

known as ‘PHOTOGENERATION OF CHARGE CARRIERS’ and

occurs throughout the N and P-type semiconductors.

• STEP 6: Due to the electric field, the electrons flow to the

N-type material and the holes flow to the P-type material.

So the N-side will become more negative and P-side will

become more positive.

• STEP 7: Now if we provide an extra path like wire from N-

type side to P-type side ,we can make all the electrons

flow through this wire, creating an electric current that we

can use.

• The electric current produced by these solar cells is DC.

• We can use this current directly in any equipment or we

can store it in batteries.

• It is the working of a unit solar cell.

• We can produce large amount of electricity by using large

solar panels constituting these smaller solar cells.

• Ocean navigation aids: Many lighthouses are now powered

by solar cells.

• Telecommunication systems: radio transceivers on

mountain tops are often solar powered.

• Photovoltaic solar generators have been and will remain

the best choice for providing electrical power to satellites

in an orbit around the Earth.

APPLICATIONS