Conjugative Effect: A Strategical Modulation of Molecular n‐Dopants for Organic Semiconductors

An efficient n‐dopant is essential to narrow the metal‐organic energy barriers for efficient organic semiconductor optoelectronic devices. Molecular n‐dopants feature clear merits of versatile molecular manipulation. However, few can achieve ohmic electron contact due to deficient design strategies. Recent studies have revealed that incorporating strong electron‐donating groups (EDGs) not only helps to increase the nucleophilicities and reduce electron affinities of n‐dopants, but also facilitates an efficient electron‐transfer process by stabilizing the resulting carbocations, thus enabling high n‐doping efficiency. A comprehensive review elucidating the underlying physics is imperative for a thorough understanding of how to tune the EDGs precisely, motivating more effective design strategies. Herein, we highlight the conjugative effect as a promising design paradigm for potent n‐dopants. This perspective delves into the fundamental principles and latest progress relating to the conjugative effect, culminating in a prospective outlook on the future design strategy of molecular n‐dopants for high‐performance organic optoelectronics.