LIQUID SOLID POLYELECTROLYTE DIODES AND SEMICONDUCTOR ANALOGS

Liquid or semisolid redox polymer electrolytes can be organized to show many characteristics of conventional solid-state semiconductor diodes. Fermi levels of redox electrolyte solutions provide a rational comparison of redox electrolyte solution mixtures at equivalence, redox ions in fixed-site polymers, corresponding redox polymer mixed conductor electrolytes, and intrinsic electronic semiconductors. Moving the Fermi levels by redox doping compares with aliovalent semiconductor doping. However the ionic mobility almost always leads to a breakdown of the analogy, and it is difficult to immobilize ions while maintaining electronic conductivity. Conditions for construction of chemical diodes that mimic p-n junctions are deduced, and reported chemical diodes are analyzed as equivalent to p-n junctions, or more nearly comparable with discharged battery cells that also show rectification.