Larger dots have more closely spaced energy levels in which the electron-hole pair can be trapped.
But only those electron-hole pairs generated in and near the depletion region contribute to current generation.
But we are not to take a mutual potential of electron-hole pair into the Hamiltonian.
An electron-hole pair is often referred to as an exciton.
These electron-hole pairs can only move along the surface.
Then, the field in the avalanche region reaches its maximum value and the population of the electron-hole pairs starts building up.
This generates an electron-hole pair and sometimes heat, depending on the band structure.
As the light source is scanned across the surface of the silicon, electron-hole pairs are generated.
Then the collision create a cold carrier and an additional electron-hole pair.
This is often described as a charge separated electron-hole pair when working with semiconductors.