Molecules-based optoelectronic devices beyond traditional sandwich-like device configuration

Abstract

Molecules-based optoelectronic devices such as organic solar cells and organic light-emitting diodes typically adopt a so-called “sandwich-like” device configuration, which comprises a transparent bottom electrode, a top-electrode and in between a thin-film active layer. Such a device structure has been widely used thanks to the optimized light-semiconductor interactions and charge-carriers injection/collection. However, in recent years, optoelectronic devices beyond traditional “sandwich” configurations have also developed rapidly, for the purpose of reducing the usage of quite-expensive transparent electrodes. For instance, novel micro-/nano-electrodes have been demonstrated by different groups to boost the performance of organic photovoltaic devices, photoconductors, phototransistors, and nano-gap electrode devices , etc . These non-sandwich optoelectronic devices are complementing each other with traditional sandwich-like diodes. In this review, we focus on the construction and functionalization of various non-sandwich-structured organic optoelectronic devices, summarize the recent representative researches and try to give a forecast on the coming advancements in this field.