Highly Sensitive, Visible Blind, Wearable, and Omnidirectional Near-Infrared Photodetectors

Abstract

Visible blind near-infrared (NIR) photodetection is essential when it comes to weapons used by military personnel, narrow band detectors used in space navigation systems, medicine, and research studies. The technological field of filterless visible blind, NIR omnidirectional photodetection and wearability is at a preliminary stage. Here, we present a filterless and lightweight design for a visible blind and wearable NIR photodetector capable of harvesting light omnidirectionally. The filterless NIR photodetector comprises the integration of distinct features of lanthanide-doped upconversion nanoparticles (UCNPs), graphene, and micropyramidal poly(dimethylsiloxane) (PDMS) film. The lanthanide-doped UCNPs are designed such that the maximum narrow band detection of NIR is easily accomplished by the photodetector even in the presence of visible light sources. Especially, the 4f electronic configuration of lanthanide dopant ions provides for a multilevel hierarchical energy system that provides for longer lifetime of the excited states for photogenerated charge carriers to transfer to the graphene layer. The graphene layer can serve as an outstanding conduction path for photogenerated charge carrier transfer from UCNPs, and the flexible micropyramidal PDMS substrate provides an excellent platform for omnidirectional NIR light detection. Owing to these advantages, a photoresponsivity of ∼800 AW is achieved by the NIR photodetector, which is higher than the values ever reported by UCNPs-based photodetectors. In addition, the photodetector is stretchable, durable, and transparent, making it suitable for next-generation wearable optoelectronic devices.

Recent Advances in 2D Rare Earth Materials

“…[ 94,95 ] 2) The RE modification of 2D materials is usually by ultrasonic, spin coating, and stirring methods. [ 96–100 ] The typical method is shown in Figure 2d, Liu et al. utilized RE trifluoromethanesulfonates (Gd(Otf) 3 ; GdL 3 for short) to modify BP.…”

“…In the hybrids, 2D materials are functionalized as supporter and energy receiver because of ultrahigh specific surface areas and superior photoelectric properties. [ 97,98 ] RE are used as light absorber because they have special absorption features including specific isolated narrow peaks or broad spectral range. [ 51,52 ] The number and position of absorption windows of RE can be controlled by doping with various RE ions, which in turn can be used for narrow and broad band detection.…”

“…realized both broadband and selectively narrowband PD with core–shell‐structured RE doped UCNPs and monolayer graphene hybrid. [ 97,98 ] By doping Yb 3+ /Er 3+ /Nd 3+ , they achieved highly sensitive PD for 325–980 nm broadband with a responsivity of about 10 2 A W −1 (Figure 6d). [ 98 ] While doping with Yb 3+ /Tm 3+ , the NIR PD with an ultrahigh photoresponsivity of 800 A W −1 for 980 nm came true.…”

“…[ 98 ] While doping with Yb 3+ /Tm 3+ , the NIR PD with an ultrahigh photoresponsivity of 800 A W −1 for 980 nm came true. [ 97 ] By novel perovskite and Er/Yb silicate nanosheet hybrid, Zhang et al. fabricated PD with remarkable spectral response at telecommunication band (≈1.54 µm) benefitted from the absorption band of Er at around 1.5 µm.…”

Materials and Designs for Wearable Photodetectors

“…Based on polymeric substrates, certain modifications have been made to these substrates to amplify the flexibility, bendability, and light absorption by forming crumpled structures . Kim et al proposed a stretchable photodetector based on a crumpled hybrid structure of graphene–gold nanoparticle with exceptional optoelectronic performance and mechanical stretchability at a tensile strain of ≈200% .…”