1. The problem statement, all variables and given/known data Its said that there is no Net current in a PN junction under equilibrium as the drift and diffusion currents cancel each other. We are talking about a Step junction at equilibrium. 2. Relevant equations Its just a qualitative analysis. 3. The attempt at a solution The only way i can think of it is as the Positive charged area in the transient region attracting the electrons in the N region, towards it. Now the particle flow due to diffusion and drift in the N region are in the same direction. Now the negative charged area in the transient region repells the electrons in P region in effect attracting the holes towards it. So here also the direction of particle flow due to diffusion and drift are in the same direction.