PHOTOACOUSTIC SPECTROSCOPY AND RADIANT ENERGY CONVERSION: THEORY OF THE EFFECT WITH SPECIAL EMPHASIS ON PHOTOSYNTHESIS

Abstract—The use of photoacoustic spectroscopy in the study of photoactive samples (photochemical, luminescent, photovoltaic) is considered. After a short explanation of the parameters important in this technique and ways of measuring them, photochemical processes are considered in detail. Relations are derived for the determination of the energy stored in photochemical products and the quantum yield for the photochemical processes.
One- and two-step photochemical processes are treated in detail and the dependence of the photo-acoustically detected products on modulation frequency is considered, showing the possibility of separating reaction steps according to their rate constants. Particular attention is given to the photosynthetic process and the potential of this method for determination of energy conversion efficiencies of the different stages of photosynthesis is demonstrated. Also the use of the technique in the study of photovoltaic processes is outlined.