Mixed-dimensional PdSe2/SiNWA heterostructures based photovoltaic detectors towards self-driven, broadband photodetection, infrared imaging and humidity sensing
The new discovery of two-dimensional (2D) palladium diselenide (PdSe2) film has attracted intensive research interest due to its unique asymmetric crystal structure and extraordinary optoelectronic properties, showing great potential for broadband and polarization photodetection. Herein, we have developed for the first time a self-driven, highly polarization-sensitive, broadband photovoltaic detector based on a PdSe2/Si nanowire array (SiNWA) heterostructure. Owing to the strong light confinement effect of SiNWA and broadband light absorption of PdSe2, the presented device exhibits a pronounced photovoltaic behavior and excellent performances in terms of a high responsivity of 726 mA/W, a large specific detectivity of 3.19×1014 Jones, an ultrabroad spectrum response range of 0.2-4.6 μm, and a fast response speed to monitor nanosecond pulsed light signal. Significantly, an impressive polarization sensitivity of 75 is achieved for the heterostructure device, which is among the highest for the 2D material-based photodetectors. Thanks to the outstanding imaging capability, the detector can record images in both near infrared (NIR) and mid-infrared (MIR) ranges with a decent resolution. Moreover, the device exhibits a light-enhanced humidity sensing behavior with a high sensitivity and a fast response/recovery time. Given these remarkable device features, the PdSe2/SiNWA heterostructure will hold great promising for high-performance, polarization-sensitive broadband photodetection, infrared imaging and humidity sensing applications.
- This article is part of the themed collection: Journal of Materials Chemistry A HOT Papers