Short-wavelength infrared (SWIR) photodetector based on multi-layer 2D GaGeTe

Abstract

Recent theoretical studies proposed that two-dimensional (2D) GaGeTe crystals have promising high detection sensitivity at infrared wavelengths and can offer ultra-fast operation. This can be attributed to their small optical bandgap and high carrier mobility. However, experimental studies on GaGeTe in the infrared region are lacking and this exciting property has not been explored yet. In this work, we demonstrate a short-wavelength infrared (SWIR) photodetector based on a multilayer (ML) GaGeTe field-effect transistor (FET). Fabricated devices show a p-type behavior at room temperature with a hole field-effect mobility of 8.6 - 20 cm2 V-1s-1. Notably, under 1310 nm illumination, the photo responsivities and noise equivalent power of the detectors with 65 nm flake thickness can reach up to 57 A/W and 0.1 nW/Hz1/2, respectively, at a drain-source bias (Vds) = 2 V. The frequency responses of the photodetectors were also measured with a 1310 nm intensity-modulated light. Devices exhibit a response up to 100 MHz with a 3dB cut-off frequency of 0.9 MHz. Furthermore, we also tested the dependence of the device frequency response on the applied bias and gate voltages. These early experimental findings stimulate the potential use of multilayer GaGeTe for highly sensitive and ultrafast photodetection applications.

Fast-Response Amorphous In2Te3 Short-Wave Infrared (SWIR) Photodetector

“…The decrease in responsivity following the increase in incident power indicates the presence of trap states/defects, which induce internal gain in the device. This result is consistent with recent findings on amorphous and 2D-based photodetectors [12][13][14]. The ratio of the photocarrier lifespan (tl) to the photocarrier transit time (tt) determines the photoresponsivity [15].…”

Low-power driven broadband phototransistor with a PbS/IGO/HfO2 stack

“…49 For quantitative analysis, the I ph dependence on light intensity can be described by simple power law relation, I ph = AP y , where the A is a constant for the given wavelength, P is the power density of the light, and y is an exponent related the photosensitivity of the device. 50 The experimental data fit to the given power law relation with the fitting parameter of y = 0.10, as shown in Fig. 3(e).…”

Theoretical investigations of the electronic and optical properties of a GaGeTe monolayer

“…16 Several experimental techniques can be used to investigate the properties of monolayer GaGeTe. For instance, high-resolution tunneling electron microscopy (HRTEM) 16,17 has been used to obtain a side view of the material, while angle-resolved photoemission spectroscopy (ARPES) 18,19 has been utilized to reveal its occupied states in calculated electronic properties. High-resolution scanning tunneling spectroscopy (STS) 20,21 can examine the entire occupied and unoccupied states of van Hove singularities in the density of states (DOS).…”