Mechanically Flexible and Multispectral Mid-Infrared Photodetector Arrays Based on All-Nanowire Circuitry

In the past few decades, infrared detection has been one of the major workhorses for varioustechnological applications in military, communication, molecular spectroscopy and biomedicalimaging. Present efforts have directed the detector development towards the middle infraredwavelength range (2–5µm) with better performance, low-cost, room temperature operation,mechanical flexibility and multispectral capability, due to the highly transparent atmosphericwindow (2–2.3µm) and strong absorption of numerous chemical molecules (2.3–5µm). At thesame time, the advent of nanotechnology has enabled unique physical properties ofsemiconducting nanotubes, nanowires and nanoparticles, etc., such as the excellent compositionand bandgap tunability as well as mechanical elasticity and robustness, which yield the idealactive materials for the flexible and multispectral infrared detection. For example, severalantimony-based nanowires have been recently explored for the mid-infrared photodetection,exhibiting superior photoconductive performance, good stability, reproducibility, impressiveresponsivity and quantum efficiency at room temperature. However, there are still significantchallenges in controlling the nanowire synthesis, understanding their fundamental properties,integrating these nultifunctional nanowire arrays, fabricating and establishing performance limitsof the photodetector circuit matrix based on these synthetic nanostructures. In this proposal, wewill emphasize on the ternary InxGa1-xSb nanowire system as the active photoconductor materialsdue to their excellent electronic transport properties and bandgap spanning from 0.17 to 0.72 eVat room temperature, corresponding to the wavelength range of 1.7–7.3 μm and covering theentire mid-infrared region. The goal is to heterogeneously integrate highly ordered and parallelarrays of optimized infrared active InxGa1-xSb nanowires and well-developed high-mobility In2O3nanowires onto plastics, interfacing the photodetector and electronic devices together to enablean all-nanowire circuitry with the on-chip integration, capable of detecting and amplifyinginfrared signals at each waveband with high sensitivity and precision. Ultimately, we willconstruct large arrays of nanowire photodetector circuitry and evaluate their performance limitswith the aim to achieve a versatile, low-cost and powerful platform to realize the mechanicallyflexible and multispectral mid-infrared photodetector arrays based on multifunctional all-nanowire circuitry.?