Question

2. In order to generate charge carriers (charge separation) in organic semiconductors, why strong donor/acceptor coupling will not work but weak donor/acceptor coupling is needed (feel free to use diagrams of frontier orbitals)?

Answer 1

THE WEAK INTERMOLECULAR INTERACTIONS INHERENT IN ORGANIC SEMICONDUCTOR MAKE THEM SUSCEPTIBLE TO DEFECT FORMATION, RESULTING IN LOCALIZED STATES IN THE BAND -GAP THAT CAN TRAP CHARGE CARRIES AT DIFFERENT TIMESCALES.CHARGE CARRIES TRAPPING IS THUS UBIQUITOUS IN ORGANIC SEMICONDUCTORS AND CAN HAVE A PROFOUND IN IMPACT ON THEIR PERFORMENCE WHEN INCORPORATED INTO OPTOELECTRONIC DEVICES. THIS REVIEWW PROVIDES ACOMPREHENSIVE OVERVIEW ON THE PHENOMENON OF CHARGE CHARRIES TRAPPING IN ORGANIC SEMICONDUCTORS, WITH EMPHASIS ON THE UNDERLYING PHYSICAL PROCESSES AND ITS IMPACT ON DEVICE OPERATION.WE FIRST DEFINE THE CONCEPT OF CGARGE CARRIES TRAP THE OUTLINE AND CATEGORIZE DIFFERENT ORIGINS OF TRAPS.NEXT WE DISCUSS THEIR IMPACT ON THE MECHANISM OF CHARGE TRANSPORT AND PERFORMENCE OF ELECTRONIC DEVICES.PROGRESS IN THE FILED I N TERM OF CHARACTERIZATION AND DETECTION OF CHARGE CHARRIES TRAPS IS REVIEWED TOGETHER WITH INSIGHTS ON FUTURE DIRECTION OF RESERCH.FINALLY , A DISSCUSSION ON THE EXPLOITATION OF TRAPS IN MEMORY AND SENSING APPLICATIONS IS PROVIED.