Broadband Photodetector With Upconversion Nanoparticles and Graphene Composite

Mukesh Kumar Thakur^1*, Akash Gupta¹, Sandip Ghosh¹, Surojit Chattopadhyay¹

¹Institute of Biophotonics, National Yang-Ming University, Taipei, Taiwan

* Presenter:Mukesh Kumar Thakur, email:mukeshkumar1111@gmail.com

A broadband photodetector based on lanthanide doped upconversion nanoparticle (UCNP) absorbers in conjunction with single layer graphene is demonstrated. Specifically, NaYF4: Yb, Er (Core UCNPs) spin coated on single layer graphene device was used, where the latter worked as the charge transport material. The photoresponsivity of this device was found to be in the order of 103 AW-1 for most of the spectrum. This is superior to those previously reported. This high responsivity enables the detector to sense weak optical signals from various domestic appliances, such as, laser pointers, cellphone flash light, and air-condition remote controllers and found it working efficiently. This work will provide new directions to the ongoing materials research for high sensitivity photo detection.

Keywords: Photodetector, Graphene, Up-conversion nanoparticles, Fluorescence, Broadband response