Hybrid 2D–0D MoS₂–PbS Quantum Dot Photodetectors

Abstract

A hybrid phototransistor consisting of colloidal PbS quantum dots and few layers of MoS2 (≥2 layers) is demonstrated. The hybrid benefits from tailored light absorption in the quantum dots throughout the visible/near infrared region, efficient charge-carrier separation at the p-n interface, and fast carrier transport through the MoS2 channel. It shows responsivity of up to 10(6) A W(-1) and backgate-dependent sensitivity.

Solution-processed semiconductors for next-generation photodetectors

“…Hence, the use of other high mobility gapped materials is a possibility, and the emergence of 2D materials with exceptional transport properties and visible bandgaps such as MoS2 has allowed for further development in the field. In 2014 PbS CQDs-MoS2 hybrid phototransistors were reported by Kufer et al, 84 which benefited from significantly lower dark currents (over an order of magnitude) whilst maintaining high responsivities. The introduction of interface states as a consequence of the chemical modification of the transport layer was found to deteriorate noise and time response characteristics, and major improvements can be expected provided these could be controlled.…”

Photogating in Low Dimensional Photodetectors

“…This phenomena has also been observed according to the experimental data in another work of Kufer et al (see Figure 1d in ref. 84). Inserting a thin insulating layer between MoS 2 and QDs can reduce the dark current at the off state and raise several orders of magnitude of the on/off ratio, as shown in Figure 8c.…”

“…Compared to the exfoliated 2D materials in QD/2D‐material hybrids,31, 41, 42, 43, 84, 85, 86, 87 the surface of MBE grown silicon should be easier to be cleaner. However, due to the imperfect quality of QDs and nonabsolutely impurity‐free spin coating, this PVFET still suffers a relatively long tail in the fall time of photocurrent (Figure 10a, right panel).…”

Monolayer MoS 2 /GaAs heterostructure self-driven photodetector with extremely high detectivity

“…Graphene based photodetectors have reported to have responsivity as high as ~10 7 A/W through the enhanced light absorption with covering semiconductor quantum dots [9]. Using similar technique of quantum dots enhanced photon absorption, MoS 2 based photodetector achieves responsivity as high as 6×10 5 A/W [10]. Detectivity of a photodetector reflects the sensitivity of the device, which is critical for the detector to detect weak signals.…”