PbE (E = S, Se) Colloidal Quantum Dot-Layered 2D Material Hybrid Photodetectors

Abstract

Hybrid lead chalcogenide (PbE) (E = S, Se) quantum dot (QD)-layered 2D systems are an emerging class of photodetectors with unique potential to expand the range of current technologies and easily integrate into current complementary metal-oxide-semiconductor (CMOS)-compatible architectures. Herein, we review recent advancements in hybrid PbE QD-layered 2D photodetectors and place them in the context of key findings from studies of charge transport in layered 2D materials and QD films that provide lessons to be applied to the hybrid system. Photodetectors utilizing a range of layered 2D materials including graphene and transition metal dichalcogenides sensitized with PbE QDs in various device architectures are presented. Figures of merit such as responsivity (R) and detectivity (D*) are reviewed for a multitude of devices in order to compare detector performance. Finally, a look to the future considers possible avenues for future device development, including potential new materials and device treatment/fabrication options.

MoS2 Based Photodetectors: A Review

“…Adapted with permission from ref. [ 49 ]. Copyright 2020, Creative Commons Attribution 4.0 Unported Licence.…”

Photoconductive PbSe thin films for infrared imaging

“…Photoconductor-based devices are generally used for IR applications such as imaging sensors and motion detection. 121 Generally, the electrodes are placed on top of the film using a mask to create ohmic contacts and have the window for incident light absorption. Two ohmic contacts (considered as source and drain electrodes) are separated by a window known as the photoactive layer.…”

“…The majority type of carriers has a shorter transit time than minority carriers and quickly traverse to an electrode, while the other electrode maintains the charge neutrality by providing additional carries, which defines the total gain. 121 The responsivity of a detector depends on the amount of gain from the device. However, if the photodetector is limited by the noise then there is a possibility that the higher gain signals will also have higher noise levels.…”

“…Because the PbSe QD can expand the range of current technologies and easily integrate with the complementary metal-oxide-semiconductor (CMOS) technology. 121 However, ligands and dangling bonds on the surface of PbSe QDs work as barriers in charge transfer, which deteriorates the performance of the devices. 114 The general device structure is the same as shown in Fig.…”

“…114 The general device structure is the same as shown in Fig. 9, while the PbSe layer is developed using a QD form of the material, which is shown and discussed by Nakotte et al 121 4.1.2 Phototransistor. Phototransistors are light-sensitive photoconductors and function like FETs, which can be referred to as photoFETs.…”