I have gone through a lot of questions but none of them ask how do the minority carriers approach the depletion layer in the first place.
When a p-n junction is formed, negative space charge accumulates at p side and positive space charge at n side. A minority carrier (say electron) from the periphery of the p side, when approaching the depletion region, should experience repulsion from the accumulation of negative space charge or ions in the depletion region, before it 'slides' down the potential barrier. The question is, minority carriers being so little in number, the probability of having thermal energy sufficient to overcome that repulsion is extremely low. So how is diffusion possible?
Is it because the space charge has no component of electric field away from the depletion region? Plus, why doesn't applied bias have any effect on the minority carrier current (according to the text books, this current is only a function of temperature). Shouldn't the reverse bias diffusion current be more than that during forward bias?