Frontier orbital model of semiconductor surface passivation: Dicarboxylic acids on n- and p-GaAs

Surface passivation due to the interaction of a given molecule with n- and p-GaAs surfaces is explained well by a highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) interaction between the frontier orbitals of the molecules and the semiconductor surface states. The observed electronic changes depend on the nature of the molecules, on the one hand, and on that of the surface states, on the other. Considering semiconductor surface passivation as a frontier orbital interaction mechanism is expected to lead to its quantitative understanding, and use of such a model for designing molecular treatments of electronic materials provides a new tool for fine-tuning semiconductor device structures.