How to characterize figures of merit of two-dimensional photodetectors

Abstract

Photodetectors based on two-dimensional (2D) materials have been the focus of intensive research and development over the past decade. However, a gap has long persisted between fundamental research and mature applications. One of the main reasons behind this gap has been the lack of a practical and unified approach for the characterization of their figures of merit, which should be compatible with the traditional performance evaluation system of photodetectors. This is essential to determine the degree of compatibility of laboratory prototypes with industrial technologies. Here we propose general guidelines for the characterization of the figures of merit of 2D photodetectors and analyze common situations when the specific detectivity, responsivity, dark current, and speed can be misestimated. Our guidelines should help improve the standardization and industrial compatibility of 2D photodetectors.

Electrically Modulated Single/Multicolor High Responsivity 2D MoTe2/MoS2 Photodetector for Broadband Detection

“…Figure a shows the time-resolved photocurrent of the MoTe 2 /MoS 2 photodetector at a wavelength of 520 nm and a bias voltage of −3 V. Even 10 3 cycle operations later, the device still exhibits a stable photoresponse. The photoresponse time is defined in terms of the rising time (τ r ), which is the time required for the stable photocurrent to increase from 10 to 90%, and the falling time (τ f ), which is the time required for it to decrease from 90 to 10% . As shown in Figure b, our device has an ultrafast response time of τ r = 36 μs and τ f = 42 μs, owing to the strong built-in potential of the MoTe 2 /MoS 2 PN junction and the atomically thin transit length in the vertical direction.…”

3D‐Heterojunction Based on Embedded Perovskite Micro‐Sized Single Crystals for Fast Photomultiplier Photodetectors with Broad/Narrowband Dual‐Mode

“…For the new inorganic-organic hybrid 3D system, we comprehensively considered all sources of noise, including the dark current, 1/f noise, generation-recombination (g-r) noise, and thermal noise. [53][54][55][56] Semiconductor devices that can operate at both forward and reverse voltages can generate large dark currents. Figure 3e compares the dark currents of the devices with different polymers as the covering layer.…”

Functionalizing nanophotonic structures with 2D van der Waals materials

“…44 Therefore, these 2D semiconductors are ideal candidates to realize active optical applications, such as light sources, optical amplification, transistors, neuromorphic computing units, and photodetection. 91–98 Moreover, a majority of 2D TMDs also possess alluring exitonic and polaritonic physical attributes that are worth studying. 74,99–102…”

“…44 Therefore, these 2D semiconductors are ideal candidates to realize active optical applications, such as light sources, optical amplification, transistors, neuromorphic computing units, and photodetection. [91][92][93][94][95][96][97][98] Moreover, a majority of 2D TMDs also possess alluring exitonic and polaritonic physical attributes that are worth studying. 74,[99][100][101][102] h-BN is a wide-bandgap (B6 eV) 2D material that was originally applied as the optimal substrate for graphene and can be used as insulating or encapsulation layers.…”