Monolayer Graphene/Germanium Schottky Junction As High-Performance Self-Driven Infrared Light Photodetector

Abstract

We report on the simple fabrication of monolayer graphene (MLG)/germanium (Ge) heterojunction for infrared (IR) light sensing. It is found that the as-fabricated Schottky junction detector exhibits obvious photovoltaic characteristics, and is sensitive to IR light with high Ilight/Idark ratio of 2 × 10(4) at zero bias voltage. The responsivity and detectivity are as high as 51.8 mA W(-1) and 1.38 × 10(10) cm Hz(1/2) W(-1), respectively. Further photoresponse study reveals that the photovoltaic IR detector displays excellent spectral selectivity with peak sensitivity at 1400 nm, and a fast light response speed of microsecond rise/fall time with good reproducibility and long-term stability. The generality of the above results suggests that the present MLG/Ge IR photodetector would have great potential for future optoelectronic device applications.

Temperature Dependent Current Transport Mechanism in Graphene/Germanium Schottky Barrier Diode

“…From the linear fit to data, barrier height was 0.42 eV. This value is comparable to barrier height measured from graphene/bulk-Ge junction (0.45 eV) [9]. Moreover, the Richardson constant, extracted from y-axis intercept of fitted line, was calculated to be 3.16 × 10 -4…”

“…Khurelbaatar et al [8] observed that graphene is effective in depinning the Fermi level in Ge. Zheng et al [9] reported the fabrication of infrared photodetector based on graphene and bulk Ge Schottky junction, where monolayer graphene used as transparent electrode. Although, produced graphene/Ge junction shows the typical rectifying behavior which can be described by the thermionic-emission theory, bulk Ge substrate is not compatible with future CMOS application and Si photonic integration.…”

The controlled growth of graphene nanowalls on Si for Schottky photodetector

“…7 Due to simple procedure and easy integration, An et al 8 developed a graphene/Si photodetector with high responsibility of 0.435A/W and the responsivity was further improved to 3A/W by Antonio et al 9 by introducing an embedded oxide layer. Other substrates like Ge, 10 GaAs, 11 InAs 12 were also combined with graphene to satisfy the needs of infrared wavelength detection.…”

Hybrid heterojunctions based on 2D materials and 3D thin-films for high-performance photodetectors

“…In addition, the device with a large specific detectivity (D * ) of~10 13 Jones showed pronounced sensitivity for weak near-infrared (NIR) light detection. Besides Si, other traditional semiconductors like germanium (Ge) [2] and GaAs [3] also exhibited great potential to integrate with atomically thin 2D materials for high-performance photodetectors.Apart from semimetallic graphene, TMDs with tunable energy spectrum enable the wide range light-matter interaction and can be utilized as optical materials. Wang et al [4] deposited MoS 2 films on Si substrate with a scalable sputtering method to construct high-quality MoS 2 /Si p-n heterojunction.…”

“…In addition, the device with a large specific detectivity (D * ) of~10 13 Jones showed pronounced sensitivity for weak near-infrared (NIR) light detection. Besides Si, other traditional semiconductors like germanium (Ge) [2] and GaAs [3] also exhibited great potential to integrate with atomically thin 2D materials for high-performance photodetectors.…”