Money in the bank: devices.

Very very likely ones:

Draw band diagrams of Ohmic, Schottky contacts with and w/o bias, for p and n materials.

Size of depletion width, wp and wn, with and w/o bias. Capacitances in mos capacitors.

Draw bands diagrams of MOSFETS, in the y or x direction (I'll give this one for sure), in triode or pinch off (and saturation?).

Draw bands of p-n diodes, short, long, revers and fwd bias, minority and majority. 8 drawings, to know by heart.

Switching a diode from Fwd to zero and from Fwd to reverse.

Derive gm in MOSFETs in saturation and triode.

Mos and p-n equivalents circtuis in all operating modes, with expressions for every component. I'd give a p-n equivalent circuit very likely.

Cut of frequency in MOSFET (unlikely, formula not given this year...but...).