The potential that prevents electrons moving from the n region into the p region is called the:

1. Diffusion across the junction leaves fixed charges behind. 2. Those charges set up a potential opposing further diffusion. 3. Since this potential tends to prevent the movement of electrons from the n region into the p region, it is called a barrier potential. 4. So the answer is the barrier potential. _Source: syllabus Physics Part II, Ch 14 'Semiconductor Electronics'_