To me personally the most fascinating aspect of mathematical device analysis is that an interplay of abstract mathematics, perturbation theory, numerical analysis and device physics is prompting the design and development of new technology.
The static semiconductor device problem is treated in an "applied mathematics" way. Qualitative properties, e.g. existence and uniqueness of solutions, and quantitative properties, particularly the structure of steady state solutions, are analysed. Physical interpretations of the mathematical results are given. Also, these results serve as a basis for the derivation and convergence analysis of numerical discretisation techniques.