NV Center Charge State Controlled Graphene-on-Diamond Field Effect Transistor Actions With Multi-Wavelength Optical Inputs

Yonhua Tzeng,Ying-Ren Chen,Yueh-Chieh Chu,Chun-Cheng Chang,Pin-Yi Li

doi:10.1109/ojnano.2020.2993007

Abstract

We demonstrate graphene-on-diamond field effect transistor (FET) actions modulated by optically excited charge state of nitrogen-vacancy (NV) centers in diamond. Palladium (Pd) metal contacts on graphene serve as the source and the drain. Negative charge state NV - center in diamond serves as the gate with diamond being the gate dielectric and produces an electric field to enhance the hole concentration in the graphene channel. The conductivity of graphene varies with negative charge state NV - center, resulting in differential conductance. The negative gate bias is removed when a NV - center is converted to an NV o center. P-type graphene channel exhibits positive differential conductance under illumination by a blue (405 nm) laser beam while on the contrary negative differential conductance by a red (633 nm) laser beam. Furthermore, by simultaneous illumination of both blue and red laser beams, effects on differential conductance decrease according to the relative intensity of the two laser beams. Graphene FETs with wavelength dependent multiple optical inputs and one electrical output in response to the charge state of NV centers in diamond has been reported.

Highlights

Graphene is a zero-gap semi-metallic 2-D material, which is atomically thin and formed by sp2 carbon-carbon bonded hexagonal lattice [1]–[3]
Two contact pads made of Pd metal deposited by RF magnetron sputtering on graphene followed by a lift-off process form the Source and the Drain
The shortest distance between two contacts is 10 μm. This test device serves as a reference for comparison with test devices made of graphene on diamond

Summary

Introduction

Graphene is a zero-gap semi-metallic 2-D material, which is atomically thin and formed by sp carbon-carbon bonded hexagonal lattice [1]–[3]. Many research groups have investigated graphene field-effect transistor (GFET) for various applications [4]–[6]. GFET with optical inputs has much room for further investigation. Diamond has a wide energy band gap (5.47 eV) [7]. Intrinsic diamond is an excellent electrical insulator exhibiting extremely high resistance at room temperature [8], [9]. By doping diamond with Boron, it forms p-type semiconductor diamond for various devices fabrication [10]. Even for an intrinsic diamond, charge-transfer doping can create a surface layer of p-type diamond suitable for electron devices [11]. Chemical, thermal, electrochemical, optical, mechanical properties of diamond have attracted a wide spectrum of applications [12]. The cost and quality of lab-grown diamond have been improving in recent years to make it more suitable for practical applications [13], [14]

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Conclusion