Electrochemical Study of Spectral Sensitization Using AgCl Sheet Crystal as a Window. Ag+ Ion Effect

With use of AgCl sheet crystal as a window, sensitized photocurrent was measured in an electrochemical cell with a lock-in amplifier. With five sensitizing dyes having different lowest vacant levels, it was found that the higher the level of the dye, the larger the sensitized photocurrent, the sensitized photocurrent increasing with decreasing pAg of the dye-bearing solution. The Ag+ ion effect can be explained by a band edge shift of the AgCl electrode, which also explains the blue desensitization recovery by Ag+ ions.