In the p-n junction diode, the majority carriers (holes in p and electrons in the n material) stand a low chance of recombining with the minority carriers (electrons in the p and holes in the n material).However, at the interface or junction between the p and n material this is initially not so. The mobile majority carriers combine and neutralise each other, leaving ionised atoms behind in the proximity of the junction. The n-region ions, having lost an electron, become positively charged and the p-region ions negatively charged through losing a hole. The resultant field across the interface inhibits the migration of majority carriers across the junction and an equilibrium condition is reached. A forward bias of about 500 mV to a silicon diode will lower this potential barrier sufficiently to enable substantial conduction to occur through the device.