The barrier potential of a p-n junction depends on: (a) type of...

The barrier potential in a p-n junction diode is a barrier which to be overcome by additional force in order to cross.

The barrier potential depends on various factors.

Different semiconductor material will have different barrier potential for the same amount of doping thus it depends on the type of semiconductor material.

For same semiconductor it is observed that for different amount of doping barrier potential is different.

For same semiconductor barrier potential changes with temperature thus barrier potential also depends on the temperature.

The barrier potential depends on type of semiconductor (for $Si{V}_{b} = 0.7$ volt and for $Ge{V}_{b} = 0.3$ volt), amount of doping and also on the temperature.