Hi, I need help to understand this section from my book. Here we are considering drift current Is of PN junction under open-circuit conditions. I don't understand why the drift current Is is indepentent of the value of the depletion layer voltage Vo. I think the voltage create an electric field that helps minority charges in N, P materials establishing drift current Is. Therefore, it is of course dependent on Vo. Can you tell me where I am wrong here?