Pure Organic Conductors Based on Protonic-Defect Induction: From Semiconductors to Organic Metals

Abstract

Abstract Protonic defects function as “lost positive point charges”, and their inclusion in molecules has great potential to control the total charge of a system. In other words, they have the ability to work as a dopant for hole injection. Carrier generation occurs when we confine and stabilize the protonic defects in hydrogen-bonding networks co-existing with a tetrathiafulvalene (TTF) skeleton, affording pure organic conductors without an addition of external dopant or electrochemical oxidation. Their conductivity varies in the range of six orders of magnitude from 10−4 to 102 S/cm, corresponding to molecular design. Moreover, anomalous isotope effects are observed in some electronic properties such as conductivity and thermopower, etc. In this account, the concept, molecular design, carrier generation and electronic properties of a series of the protonic-defect induced pure organic conductors are comprehensively reviewed from semiconductors to organic metals.