P-N junction diode

In p-type hole are majority carrier and electrons are the minority carrier

in n-type semiconductor, the electrons are majority carrier and hole are the minority carrier

then p-type and n-type doping

so we can convert silicon crystal into the pn junction

so the given diagram shows the junction . Here junction is the border where p-type and n-type region meet and this silicon crystal convert into pn junction

p-type and n-type as the diode because here the p-type and n-type region act as like a two-electrode

so understanding the pn junction we can understand all kind of semiconductor device, so in this p-type region each circle negative sign represented the trivalent atom the positive side represented the hole atom

similar n-type positive sign represent pentavalent atom and negative electron

p side electron are majority carrier and whenever this pn region join electrodes from the n-side start diffusing towards p-type

whenever electron enter the p-type region it becomes the minority carrier and surrounded by so many holes