1 research outputs found
Thermally Driven Field Emission from Zinc Oxide Wires on a Nanomembrane Used as a Detector for Time-of-Flight Mass Spectrometry
Mass spectrometry
is a crucial technology in numerous applications,
but it places stringent requirements on the detector to achieve high
resolution across a broad spectrum of ion masses. Low-dimensional
nanostructures offer opportunities to tailor properties and achieve
performance not reachable in bulk materials. Here, an array of sharp
zinc oxide wires was directly grown on a 30 nm thin, free-standing
silicon nitride nanomembrane to enhance its field emission (FE). The
nanomembrane was subsequently used as a matrix-assisted laser desorption/ionization
time-of-flight mass spectrometry detector. When ionized biomolecules
impinge on the backside of the surface-modified nanomembrane, the
currentemitted from the wires on the membrane’s front
sideis amplified by the supplied thermal energy, which allows
for the detection of the ions. An extensive simulation framework was
developed based on a combination of lateral heat diffusion in the
nanomembrane, heat diffusion along the wires, and FE, including Schottky
barrier lowering, to investigate the impact of wire length and diameter
on the FE. Our theoretical model suggests a significant improvement
in the overall FE response of the nanomembrane by growing wires on
top. Specifically, long thin wires are ideal to enhance the magnitude
of the FE signal and to shorten its duration for the fastest response
simultaneously, which could facilitate the future application of detectors
in mass spectrometry with properties improved by low-dimensional nanostructures