Electrical properties of nitrogen-doped 4-aminomorpholine functionalized-graphene quantum dot-based heterojunction diode

Abstract

The scientific world has recently begun to pay close attention to graphene quantum dots (GQDs) semiconductor junctions (GQDs-S), particularly because of their significant potential to open doors to new research fields, including sensing, communication, and detection. GQDs can be functionalization with various functional groups to enhance their properties. In this study, 4-aminomorpholine (4A-MORP) substituted N-doped GQDs (4A-MORP N-GQDs) were synthesized from the reaction of 4A-MORP and citric acid in aqueous medium in an autoclave. The synthesized 4A-MORP N-GQDs were characterized by ultraviolet-visible (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Next, the Ag/4A-MORP/N/GQDs/p-Si diode was fabricated. The properties of the Ag/4A-MORP/N/GQDs/p-Si Schottky diode were investigated using current-voltage (I-V) measurements in the dark and under 100 mW/cm2 illumination intensity (at +/- 3 V and 300 K). Cheung's and Norde's functions, as well as classical thermionic emission (TE) theory, were used to analyze the diode's ideality factor (n), barrier height (Phi b), and series resistance (Rs). The barrier heights (Phi b) of the Ag/4A-MORP/N/GQDs/p-Si diode obtained from these approaches are 0.74 eV and 0.94 eV in the dark and under 100 mW/cm2 illumination intensity, respectively. At +/- 3 V, the diode's rectification ratios (RR) in the dark and under 100 mW/cm2 illumination intensity are calculated to be approximately 1.02 x 102 and 1.16 x 101, respectively. According to the results obtained, the produced Ag/4AMORP/N/GQDs/p-Si exhibits Schottky diode behavior, and these results are expected to be instrumental in better understanding electronic technology based on functionalised graphene quantum dots.