Poole-Frenkel ionization of excitons in solid Kr
Fachbereich Physik der Philipps-Universität Marburg
and Wissenschaftliches Zentrum für Materialwissenschaften,
Renthof 5, D-35032 Marburg, Germany
Accepted: 11 June 1997
During vacuum-UV excitation of the excitons in solid Kr photoconductivity was observed. For applied voltages below 50 V the photocurrent spectrum reflected the number of excitons produced in the bulk, whereas at higher voltages the contribution of excitons in a thin surface layer, including longitudinal and surface excitons, dominated the spectrum. These findings can be explained under the assumption of a Poole-Frenkel effect in the electrical fields produced by surface charges generated during the irradiation.
PACS: 79.70.+q – Field emission, ionization, evaporation, and desorption / 71.35.-y – Excitons and related phenomena / 72.40.+w – Photoconduction and photovoltaic effects
© EDP Sciences, 1997