Influence of Light Intensity on Internal Field-Assisted Photoemission Characteristics of Ag-BaO Thin Film
入射光强对Ag-BaO薄膜内场助光电发射特性的影响

Enhanced photoemission of Ag-BaO thin film under different light intensity was observed when an internal field-assisted bias was applied to the thin film. The increasing process of the photoemission current with the applied bias consists of fast stage and slow one, and between these two stages there is a transitional voltage related to the light intensity. The enhanced photoemission is explained as the decrease of interfacial barrier between Ag particles and BaO matrix and the degradation of vacuum level at the surface. The existence of transitional vo ltage is due to the different effects of the interfacial barrier and vacuum leve l on the photoemission enhancement. The influence of light intensity on the tran sitional voltage comes from the variations in the interior electric field, which are caused by the photogenerated-carriers in the thin films.