Enhancement of Electronic and Optoelectronic Performance of the InSe Multilayer by Surface Transfer Engineering

Abstract

Indium selenide (InSe) is considered an ideal two-dimensional material for infrared light detection owing to its high carrier mobility and narrow band gap. Here, we demonstrate a considerable enhancement in the performance of an InSe phototransistor via surface functionalization with an In layer. Electron mobility in InSe increased by almost 59 times after surface functionalization using a 20 nm thick In layer. Furthermore, compared with InSe/h-BN, In/InSe/h-BN-based photodetectors exhibited an almost 3-fold increase in photoresponsivity and external quantum efficiency at 940 nm owing to an enhancement of the surface charge transfer. First-principles calculation and Raman and photoluminescence spectroscopy analyses confirmed the occurrence of a considerable surface charge transfer at the In/InSe interface. The tunability of the surface transfer efficiency via doping establishes the potential of InSe for future use in optoelectronic devices based on two-dimensional materials.

High-Performance InSe Photodetector Induced by Synergetic Surface Plasmon Resonance and Surface Engineering

“…In addition, the PL spectra of thin-layer InSe shown in Figure f exhibit a typical peak photon energy at around 1.38 eV (946 nm), in good agreement with previous reports. , However, the PL signal was completely suppressed after deposition of the In layer. This can be ascribed to the charge transfer process between the In and InSe layers as well as the fact that neutral excitons are the dominant contributors to the PL signal of the InSe layer …”