title: Multifunctional graphene optoelectronic devices capable of detecting and storing photonic signals.
abstract: The advantages of graphene photodetectors were utilized to design a new multifunctional graphene optoelectronic device. Organic semiconductors, gold nanoparticles (AuNPs), and graphene were combined to fabricate a photodetecting device with a nonvolatile memory function for storing photonic signals. A pentacene organic semiconductor acted as a light absorption layer in the device and provided a high hole photocurrent to the graphene channel. The AuNPs, positioned between the tunneling and blocking dielectric layers, acted as both a charge trap layer and a plasmonic light scatterer, which enable storing of the information about the incident light. The proposed pentacene-graphene-AuNP hybrid photodetector not only performed well as a photodetector in the visible light range, it also was able to store the photonic signal in the form of persistent current. The good photodetection performance resulted from the plasmonics-enabled enhancement of the optical absorption and from the photogating mechanisms in the pentacene. The device provided a photoresponse that depended on the wavelength of incident light; therefore, the signal information (both the wavelength and intensity) of the incident light was effectively committed to memory. The simple process of applying a negative pulse gate voltage could then erase the programmed information. The proposed photodetector with the capacity to store a photonic signal in memory represents a significant step toward the use of graphene in optoelectronic devices.
authors: †SKKU Advanced Institute of Nanotechnology (SAINT), ‡Department of Physics, and §School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors: Sukjae
authors: S
authors: Jang
authors: †SKKU Advanced Institute of Nanotechnology (SAINT), ‡Department of Physics, and §School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors: Euyheon
authors: E
authors: Hwang
authors: †SKKU Advanced Institute of Nanotechnology (SAINT), ‡Department of Physics, and §School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors: Youngbin
authors: Y
authors: Lee
authors: †SKKU Advanced Institute of Nanotechnology (SAINT), ‡Department of Physics, and §School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors: Seungwoo
authors: S
authors: Lee
authors: †SKKU Advanced Institute of Nanotechnology (SAINT), ‡Department of Physics, and §School of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors: Jeong Ho
authors: JH
authors: Cho
keywords: Graphene; flexible optoelectronics; nonvolatile memory; photodetector; photogating; plasmonic