Download Document

Photoelectron Spectroscopy
• Lecture 7 – instrumental details
– Electron detectors
– Instrumental examples
Electron Detectors
Channel Electron Multiplier
Microchannel Plate
CCD detectors can also be used, typically with a
phosphor screen to convert electrons to photons
Examples of Spectrometers
Gas-Phase Photoelectron Instrument
Minus voltage
Plus voltage
+
hν
Photon
Source
Sample
Chamber
Photon Induces the
Photoelectric Effect.
Electron Kinetic
Energy Analyzer
Electrons are
separated
according to
kinetic energy
Electron
Counter
Computer
Control
Output is plot of
Ionization Energy
vs. Counts
Surface Photoelectron Instrument
Sample Prep
and Storage
Fast
Entry
Main
Analysis
Photoelectron Imaging Instrument
Mass-Selected Gas-Phase Photoelectron Instrument
Time-of-flight mass spectrometer magnet
2.5 m
MCP
(mass
detector)
5x10-11 Torr
Time-of-flight
magnetic botter
photoelectron
spectrometer
Electrospray
Ionization source
Z-stack MCP
(photoelectron
detector)
4.0 m