High sensitivity graphene-Al2O3passivated InGaAs near-infrared photodetector

Bokuan Yang; Yangyang Zhao; Jun Chen

doi:10.1088/1361-6528/ac1a43

High sensitivity graphene-Al₂O₃passivated InGaAs near-infrared photodetector

Nanotechnology. 2021 Aug 20;32(45). doi: 10.1088/1361-6528/ac1a43.

Authors

Bokuan Yang¹, Yangyang Zhao¹, Jun Chen¹

Affiliation

¹ Jiangsu Engineering Research Center of Novel Optical Fiber Technology and Communication Network, School of Electronic and Information Engineering, Soochow University, Suzhou, Jiangsu, 215006, People's Republic of China.

PMID: 34343973
DOI: 10.1088/1361-6528/ac1a43

Abstract

InGaAs/graphene Schottky photodiode has a low Schottky barrier height (SBH) which induces high dark current density. In this paper, an Al₂O₃thin film is inserted between the layer of InGaAs and graphene to suppress the dark current density for nearly two orders of magnitude. As a result, it is a distinct enhancement on the performance that the graphene/Al₂O₃/InGaAs near-infrared photodetector (NIR PD) under -0.4 V has a better responsivity of 523.77 mA W^-1and a better detectivity of 4.42 × 10¹⁰cm Hz^1/2/W to 1064 nm incident light than the graphene/InGaAs NIR PD. Moreover, graphene/Al₂O₃/InGaAs NIR PD also has a great response to 1550 nm incident light and the degradation on the device was observed. With the calculation, an increase of 0.122 eV on the Schottky barrier height (SBH) of graphene/Al₂O₃/InGaAs was founded. The result is expected to promote the application of the graphene NIR PD to the novel sensors.

Keywords: Al2O3 thin film; InGaAs; graphene; near-infrared photodetector.