The paper summarizes the theoretical and experimental work on the effects of electric fields on the spectroscopic properties of molecules confined at metal electrodes. Both absorption and fluorescence are discussed in a unified manner. The first order interaction between the molecule and the static electric field leads to a shift in the absorption line called the Stark shift. In isotropic media the Stark shift depends on the square of the electric field strength, while at metal interfaces the dependence is linear. The effects of the electric field on molecules at electrode interfaces can be observed using electromodulated reflectance (EmR) and electromodulated fluorescence (EmF). The absorption of light by a molecule is followed by relaxation back to the ground state, with a radiative component called fluorescence. The interface electric field can produce substantial changes in the intensity of fluorescence of confined molecules since the excited state can interact strongly with the metal electrons thus modulating the quantum yield.
Encyclopedia of Surface and Colloid Sciences
absorption, fluorescence, immobilized, quantum yield, stark spectroscopy
and Wang, L.
Stark Spectroscopy at Metal Surfaces, Encyclopedia of Surface and Colloid Sciences
(Accessed March 2, 2024)