Atomically thin materials such as graphene are uniquely responsive to charge transfer from adjacent materials, making them ideal charge transport layers in phototransistor devices. Effective implementation of organic semiconductors as a photoactive layer would open up a multitude of applications in biomimetic circuitry and ultra-broadband imaging but polycrystalline and amorphous thin films have shown inferior performance compared to inorganic semiconductors. Here, we utilize the long-range order in rubrene single crystals to engineer organic semiconductor-graphene phototransistors surpassing previously reported photo-gating efficiencies by one order of magnitude. Phototransistors based upon these interfaces are spectrally selective to visible wavelengths and, through photoconductive gain mechanisms, achieve responsivity as large as 10^7 A/W and a detectivity of 1.5 10^9 Jones at room temperature. These findings point towards implementing low-cost, flexible materials for amplified imaging at ultra-low light levels.
@article{arxiv.1710.00630,
title = {Highly efficient rubrene-graphene charge transfer interfaces as phototransistors in the visible regime},
author = {Gareth F. Jones and Rui M. Pinto and Adolfo De Sanctis and V. Karthik Nagareddy and C. David Wright and Helena Alves and Monica F. Craciun and Saverio Russo},
journal= {arXiv preprint arXiv:1710.00630},
year = {2017}
}
Comments
Published in Advanced Materials. Supplementary material available at http://onlinelibrary.wiley.com/doi/10.1002/adma.201702993/full