Nanoprinted Quantum Dot–Graphene Photodetectors

Abstract

State-of-the-art semiconductor-based infrared photodetectors such as epitaxially grown InGaAs and HgCdTe are expensive, not readily compatible with complementary metal-oxidesemiconductor fabrication, require sophisticated processing, Photodetectors utilizing graphene field-effect transistors sensitized by colloidal quantum dots exhibit high responsivities under infrared light illumination. Precise, microscopic spatial control over quantum dot deposition is required to gain deeper insight into device mechanisms, optimize device performance, and enable new device architectures and applications. The latter may eventually include photodetectors with subwavelength device dimensions. Here, infrared photodetectors are fabricated by electrohydrodynamic nanoprinting of colloidal PbS quantum dots onto graphene field-effect transistors with varying quantum dot layer thicknesses on a single substrate, demonstrating the potential of the method for realizing small footprint detectors with high spatial resolution. Remarkably, while the responsivity of the photodetectors increases with increasing layer thicknesses up to 130 nm, the noise current is found to be independent of the layer thickness. In addition, the responsivity and noise current are both linearly dependent on the applied drain voltage and drain current. As a result, the specific detectivity is independent of the drain voltage, and the detector can be operated at lower drain voltages thus reducing power consumption. Finally, specific detectivities of at least 10 9 Jones at 1200 nm are obtained, without degradation of the charge carrier mobilities in graphene from the electrohydrodynamic printing.

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

“…As a result, the specific detectivity is independent of the drain voltage, and the detector can be operated at lower drain voltage thus reducing power consumption. D* values of at least 10 9 Jones are reported without degradation of the charge carrier mobilities in graphene from the electrohydrodynamic printing of QDs [137].…”

“…Electrohydrodynamic nanoprinting of colloidal PbS QDs onto graphene FETs with varying quantum dot layer thicknesses is a potential method for realizing small footprint detectors with high spatial resolution [137]. The responsivity of the photodetectors increases with increasing layer thicknesses up to 130 nm.…”

3D Nanophotonic device fabrication using discrete components

“…Figure 10 demonstrates the potential of inkjet printing as a versatile 3D nanofabrication technique. Several studies have investigated the minimum achievable feature size and 3D capability of the inkjet printing platform [128,[172][173][174][175][176]. Galliker et al printed gold nanopillars with diameter around 50 nm and aspect ratio of 17 using a nozzle diameter of 1 μm [172].…”

Mesoporous Matrices as Hosts for Metal Halide Perovskite Nanocrystals

“…[ 6 ] One of the means by which this is achieved is through the reduction of the semiconductor size and dimensionality, [ 7,8 ] approaches that have already been put into practice into actual perovskite devices with improved photoluminescence quantum efficiency, spectral properties, and stability. [ 9–14 ]…”