Trapped Photons Induced Ultrahigh External Quantum Efficiency and Photoresponsivity in Hybrid Graphene/Metal-Organic Framework Broadband Wearable Photodetectors

摘要

Metal-organic frameworks (MOFs) have recently emerged as attractive materials for their tunable properties, which have been utilized for diverse applications including sensors, gas storage, and drug delivery. However, the high porosity and poor electrical conductivity of MOFs restrict their optoelectronic applications. Owing to the inherent tunability, a broadband photon absorbing MOF can be designed. Combining the superior properties of the MOFs along with ultrahigh carrier mobility of graphene, for the first time, this study reports a highly sensitive, broadband, and wearable photodetector on a polydimethylsiloxane substrate. The external quantum efficiency of the hybrid photodetector is found to be 5 x 10(8)%, which exceeds all the reported values of similar devices. The porosity of the MOF and ripple structure graphene can assist the trapping of photons at the light-harvesting layer. The device photoresponsivity is found to be 10(6) A W-1 with a response time of 150 ms, which is approximately ten times faster than the current standards of the graphene-organic hybrid photodetectors. In addition, utilizing the excellent flexibility of the graphene layer the wearability of the devices with stretchability up to 100% is demonstrated. The unique discovery of MOF-based high-performance photodetectors opens up a new avenue in organic-inorganic hybrid optoelectronics.