Local secondary-electron emission spectra via scanning probe energy loss spectroscopy

The process of local secondary-electron emission spectra from a graphite surface using a scanning probe energy loss spectroscopy (SPELS) instrument was analyzed. The SPELS system employed a scanning tunneling microscope with X-scan capability, modified to screen the electrical fields, that occur due to the high voltages applied to the pie scanner and tip holder, and a hemispherical electron energy analyzer mounted on top of the microscope. It was found that SPELS spectra of graphite taken with different field-emission voltages can provide local electronic information by energy loss spectra and secondary-electron emission spectra. It was also found that the screening of the electric field via the use of coaxial or embedded field emission also provides pie-resolved spectra.