Atomic emission spectroscopy of electrically triggered exploding nanoparticle analytes on graphene/SiO2/Si substrate

Abstract

The authors report a device technology that promises chip-scale atomic emission spectroscopy operating in air ambient at room temperature with low voltage pulses. Analytes are placed on top of a graphene/SiO2/Si substrate and are atomized for atomic luminescence under electrical excitation. Here, the graphene is designed to serve as an electron-transparent conducting electrode. Under proper voltage pulses applied, the thin insulating layer (10-nm SiO2) breaks down and forms nanoscale leakage channels. Electrons induced at the SiO2/Si interface then emit into the void channels and ballistically travel into the anode (graphene) side. Kinetic electrons are injected into analytes inducing explosions of analyte material. This explosive fragmentation produces atoms in various excited states. The excited atoms then relax producing characteristic luminescence.