Space Charge Layer Model: Verification by UPS, Ionic Conductivity, and Photographic Effect of AgBr

Ultraviolet photoelectron spectroscopy (UPS) has been successfully applied to the measurement of the height of the top of the valence band (VB) of the surface of AgBr layers on Ag substrates for the verification of the space charge layer (SCL) model, according to which the positive SCL of AgX grains influences their photographic effects by causing the difference in the electronic energy levels between their surface and interior. The depression of the positive SCL of AgBr caused by such adsorbates as stabilizers and antifoggants was characterized by the decrease in the height of the top of the VB of the surface of AgBr layers, the increase in the surface potential of AgBr grains and the inrease in the fraction of the grains forming latent image centers at sulfur sensitization centers on the surface.