silicon chips
silicon is a element,in sand and quartz.semiconductor chips and transistors are created by silicon.silicon is the heart of electronic device.silicon crystals look metallic,they are not.infact,metals.
device that use radio waves depends on semiconductor(chips or transistor).all of the outer electrons in a silicon crystal are involved in perfect covalent bonds,creates a'lattice'.so,they can't move around and not allow the flow of current.
metals are conductor of electricity.because they usually have free electrons.so it easily move between atoms,and electricity involves the flow of electrons.
silicon lattice having perfect bonding of atoms in their neighbour side.so,no way of electrons to flow in silicon.but we change all this by the process,DOPING.
mixing small amount of impurities in silicon,makes it into a conductor by doping.they are two types.N-type,and P-type.
N-type:mixing of phosphorus or arsanic(having 5 outer electron,but silicon having 4,so the 5th electrons free to move)by very little quantity of impurities creates enough free electrons to allow electric current to flow through the silicon.
p-TYPE:boron or gallic(having 3 outer electron).absence of 4th makes effect of +ve charge.it makes a hole in the lattice.holes can conduct electricity.
silicon is a insulator.by this doping,silicon changes into semiconductor.
diode is the beginning point of semiconductor.device that block flow of current in one direction anwhile letting it in another direction is called diode.diode created by 2 layer,and transistor is created by 3 layer.transistor can act as switch or amplifier.transistor look like two diode back to back.it blocks current in both way.when you apply current in the center layer,it passes current.
silicon chip is a piece of silicon that hold thousands of transistors,will transistors act as switches,you can create boolean gates.and with boolean gates you can create microprocessor chips and other devices.