City Research Online

Abstract

A new doping technique called Electrode Penetration Doping has been developed in order to produce inelastic electron tunnelling spectra of volatile solvents such as benzene which previously had proved, impossible to dope by other methods. An investigation into the doping mechanism revealed a large number of pores in the upper (lead) electrode through which the organic molecules are thought to pass. Additionally,
the same investigation revealed the rough surface nature of both the aluminium and lead electrodes as being due to the rough substrate used for tunnelling experiments.
Using a model of the junction deduced from the above investigation, it has been possible to explain several previously unexplained phenomena such as boosting and
instabilities.

A computerised spectrometer has been constructed in order to average several scans of one spectrum thus reducing random low frequency noise which cannot be re-
moved by increasing the detector time constant. The microprocessor used for controlling the spectrometer is also able to store spectral data on minifloppy discs. The
microprocessor has also been interfaced to the University's mainframe computer to allow larger spectral processing programmes to be implemented.

Finally, a new form of spectroscopy is proposed. A.S.E.T. (Anti-Stokes' Electron Tunnelling) spectroscopy has been devised in order to circumvent insulator break-
down problems occurring in normal inelastic electron tunnelling spectroscopy. The technique involves using a tunnel junction with a translucent upper electrode, selectively exciting the adsorbed species using a tuneable radiation source and then interacting tunnelling electrons with the excited species. The results presented are of
a preliminary nature only, yet they do show that an effect is occurring and that a future investigation will prove worthwhile.

Publication Type:	Thesis (Doctoral)
Subjects:	Q Science > QD Chemistry T Technology > TA Engineering (General). Civil engineering (General) T Technology > TP Chemical technology
Departments:	School of Science & Technology School of Science & Technology > School of Science & Technology Doctoral Theses Doctoral Theses

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