Near-Field Energy Transfer Using Nanoemitters For Optoelectronics

Effective utilization of excitation energy in nanoemitters requires control of exciton flow at the nanoscale. This can be readily achieved by exploiting nearfield nonradiative energy transfer mechanisms such as dipole-dipole coupling (i.e., Forster resonance energy transfer) and simultaneous two-way electron transfer via exchange interaction (i.e., Dexter energy transfer). In this feature article, we review nonradiative energy transfer processes between emerging nanoemitters and exciton scavengers. To this end, we highlight the potential of colloidal semiconductor nanocrystals, organic semiconductors, and two-dimensional materials as efficient exciton scavengers for light harvesting and generation in optoelectronic applications. We present and discuss unprecedented exciton transfer in nanoemitter-nanostructured semiconductor composites enabled by strong light-matter interactions. We elucidate remarkably strong nonradiative energy transfer in self-assembling atomically flat colloidal nanoplatelets. In addition, we underscore the promise of organic semiconductor-nanocrystal hybrids for spin-triplet exciton harvesting via Dexter energy transfer. These efficient exciton transferring hybrids will empower desired optoelectronic properties such as long-range exciton diffusion, ultra-fast multiexciton harvesting, and efficient photon upconversion, leading to the development of excitonic optoelectronic devices such as exciton-driven light-emitting diodes, lasers, and photodetectors.