Light-Induced Charge Separation at Sensitized Sol−Gel Processed Semiconductors

The photophysical properties of molecular sensitizers incorporated within sol−gel processed wide-bandgap semiconductors are reviewed. Excited-state interfacial electron transfer in sensitized colloids and colloidal films provides a basis for the conversion of photons into potential energy. Sol−gel processed materials with high transparency in the visible region allow charge separation and recombination processes to be quantified spectroscopically. The yields and dynamics of these processes are reviewed for a wide variety of sensitizer−semiconductor assemblies. Implications for solar energy conversion and other molecular device applications are discussed.