Electrogenerated Chemiluminescence: 34. Photo‐Induced Electrogenerated Chemiluminescence and Up‐Conversion at Semiconductor Electrodes

Photosensitized oxidations or reductions at p‐ and n‐type and semiconductor electrodes of aromatic species in aprotic solvents leading to electrogenerated chemiluminescence (ECL) are described. The energy of the irradiating light equal to the bandgap energy of the semiconductor and the electrical energy input couple to produce excited states which eventually produce emission at shorter wavelengths. Intense ECL is observed by alternately generating radical cations and radical anions at an illuminated semiconductor electrode with smaller potential excursions than required on metal (platinum) electrodes.