Performance of graphene/P-InP Schottky diode enhanced by silver nanoparticles

Abstract

In this paper, a Schottky junction near-infrared photodetector is formed by the combination of two-dimensional(2D) material graphene and P-InP. By using the surface plasmon resonance of silver nanoparticles(Ag NPs), a layer of Ag NPs was spin-coated on the single-layer graphene(SLG)/P-InP structure to improve the response rate. As a result, the response rate and detection rate were improved, and the response rate was increased from 1.227 mA/W to 7.876 mA/W, the detection rate was also increased from 5.052 × 109 cmHz1/2W−1 to 1.178 × 1010 cmHz1/2W−1. Since the defects and dangling bonds on the semiconductor surface can be reduced by depositing a thin oxide layer between graphene and semiconductor as a passivation layer, a 2 nm Al2O3 layer was inserted between graphene and P-InP to form Ag NPs/SLG/Al2O3/P-InP structure. The Schottky barrier height was increased from 0.675 eV to 0.815 eV, the response rate was further greatly improved, up to 40.195 mA/W, and the detection rate was also increased to 6.08 × 1010 cmHz1/2W−1.