Boosting the Sensitivity of WSe₂ Phototransistor via Janus Interfaces with 2D Perovskite and Ferroelectric Layers

Abstract

Hybrid systems have recently attracted increasing attention, which combine the special attributes of each constitute and create interesting functionalities through multiple heterointerface interactions. Here, we design a two-dimensional (2D) hybrid phototransistor utilizing Janus-interface engineering, in which the WSe 2 channel combines light-sensitive perovskite and spontaneously polarized ferroelectrics, achieving collective ultrasensitive detection performance. The top perovskite (BA 2 (MA) 3 Pb 4 I 13 ) layer can absorb the light efficiently and provide generous photoexcited holes to WSe 2 . WSe 2 exhibit p-type semiconducting states of different degrees due to the selective light-operated doping effect, which also enables the ultrahigh photocurrent of the device. The bottom ferroelectric (Hf 0.5 Zr 0.5 O 2 ) layer dramatically decreases the dark current, which should be attributed to the ferroelectric polarization assisted charge trapping effect and improved gate control. As a whole, our phototransistors show excellent photoelectric performances across the ultraviolet to near-infrared range (360−1050 nm), including an ultrahigh ON/OFF current ratio > 10 9 and low noise-equivalent power of 1.3 fW/Hz 1/2 , all of which are highly competitive in 2D semiconductor-based optoelectronic devices. In particular, the devices show excellent weak light detection ability, where the distinguishable photoswitching signal is obtained even under a record-low light intensity down to 1.6 nW/cm 2 , while showing a high responsivity of 2.3 × 10 5 A/W and a specific detectivity of 4.1 × 10 14 Jones. Our work demonstrates that Janus-interface design makes the upper and lower interfaces complement each other for the joint advancement into high-performance optoelectronic applications, providing a picture to realize the integrated engineering on carrier dynamics by light irradiation, electric field, interfacial trapping, and band alignment.

Wavelength-Resolved Janus Biosensing Interface for Ratiometric Electrochemical Analysis

“…These interfaces combine the special attributes of each component to construct attractive features. 28 Therefore, the combination of the photoexcitation strategy and Janus interface would provide a promising method for constructing high-performance biosensors.…”

“…Recently, Janus interfaces have been designed to enable high-performance optoelectronic applications based on highly photoactive perovskites and spontaneously polarized ferroelectrics with photoresponses at different wavelengths. These interfaces combine the special attributes of each component to construct attractive features . Therefore, the combination of the photoexcitation strategy and Janus interface would provide a promising method for constructing high-performance biosensors.…”

Electret Modulation Strategy to Enhance the Photosensitivity Performance of Two-Dimensional Molybdenum Sulfide

“…A quasi-permanent external charge is formed on the surface of PTFE, which enables it to have good charge storage performance . More importantly, due to the high resistivity and dielectric strength (an indication of low dielectric loss), the generated nonvolatile electric field may be employed to regulate the charge transport in 2D materials . At present, nevertheless, there is limited research on this issue, much less tuning the photoresponse of TMD channels.…”

Self‐Assembly of Janus Graphene Oxide via Chemical Breakdown for Scalable High‐Performance Memristors

“…[3][4][5] Janus two-dimensional (2D) materials, mainly transition metal dichalcogenides (e.g., WSe 2 and MoS 2 ) and dielectrics (e.g., graphene oxide), have raised great interest in the field of optoelectronics. [6][7][8] However, the main challenge of Janus materials (especially 2D materials) is to find a simple, economical, and environmentally friendly synthesis method.…”