Review according to the reference textbook, do more exercises, and study and understand the real questions over the years. It is not too difficult to reach 120- 130.

The main difficulty is that the basic knowledge such as holes, space charge areas and Brillouin zones in noun interpretation will appear every year; Regarding the calculation problem, the carrier concentration is mainly calculated according to the conditions, and the Einstein relation is deduced. Generally, the most basic formula is used to calculate the ionization stage. In addition, dozens of diagrams such as heterojunction, gold semi-contact and pn junction are basically sub-topics, so we must grasp them well.