Performance-enhanced photodetector based on ZnO/MWCNTs/MXene hybrid layer: Enhanced charge transport and hot-electrons injection

Abstract

The strategy of sandwiching MXene into ZnO/multi-walled carbon nanotubes (MWCNT) hybrid layer for improving ZnO-based photodetector performances has been proposed. Specifically, the designed photodetector achieves high detectivity (D⁎) and responsivity (Rp), upping to ∼ 2.9 × 1011 Jones and 99.68 mA/W respectively. In addition, the photocurrent derivative is used to explain the time-revolved charge transfer process. Under light-on and -off, photocurrent derivative increased by ∼ 101.61 and 96.38 times respectively. The reason for this phenomenon may be due to the synergism of charge-transfer enhancement and hot-electron injection. On the one hand, the introduction of MWCNT can promote the charge transfer in ZnO layer, which may benefit from the interface modification. On the other hand, the non-radiative decay caused by Localized Surface Plasmon Resonance (LSPR) can produce hot electrons with sufficient energy in MXene, which can through the space charge layer (SCL) between ZnO and MXene and be collected in ZnO.