A bioinspired Au-Cu1.97S/Cu2S film with efficient low-angle-dependent and thermal-assisted photodetection properties

iScience. 2021 Feb 9;24(3):102167. doi: 10.1016/j.isci.2021.102167. eCollection 2021 Mar 19.

Abstract

Inspired by the geological processes, this study develops an innovative low-concentration-ratio H2 reduction method to reduce the stoichiometric Au-CuS nanoparticles to produce completely reduced stoichiometric Cu2S with "invisible" Au achieved for solid solution Au enhancement. A stable Au-Cu1.97S/Cu2S micro/nano-composite is then formed by spontaneous oxidation. From this composite, in combination with biomimetic technology, an omnidirectional photoabsorption and thermoregulated film (Au-Cu1.97S/Cu2S-C-T_FW) is designed and fabricated as a photothermal-assisted and temperature-autoregulated photodetector for broadband and low-angle-dependent photodetection that presents good performance with high responsivity (26.37 mA/W), detectivity (1.25×108 Jones), and good stability at low bias (0.5 V). Solid solution Au exhibits significantly enhanced photodetection (1,000 times). This study offers a new concept for improving the stability and photoelectric properties of copper chalcogenides. Moreover, it opens up a new avenue toward enhancing the performance of optoelectronic and photovoltaic devices using solid solution metal atoms and thermal-assisted, anti-overheating temperature autoregulation.

Keywords: Devices; Materials Property; Nanomaterials.