Dynamic disorder impact on quantum efficiency of photosystems

Photosystem I (PS I) of the green plant and algae shows the highest quantum light conversion yield in nature. It is unexpected that the average lifetime of excitation decay in a spectrally heterogeneous antenna of PS I is several times shorter than that of PS II which is comparable in size and, moreover, is almost spectrally homogeneous. Recently it has been found, that clustering of the reaction centers surrounded by circular antennae (LH1-RC) also accelerates the conversion of light energy. The aim of this work is to reveal what changes in light-harvesting antenna structures result in higher light energy conversion quantum efficiency. Relevance and novelty of the topic are determined by 1) in spite of huge accumulated kinetic spectroscopy data on the PS I of plants, bacteria, and algae, there is no uniform model of all these systems uncovering the origin of extraordinary quantum efficiency; 2) In 2015, the structure of the plant PS I with all antenna complexes has been determined with 0.2 nm accuracy, that enables detailed calculations of open quantum system states; 3) Although the first kinetic spectroscopy data of LH1-RC complex clusters were published in 2016, the enhancement effect of LH1-RC clustering on the system efficiency has not been explained so far.
For more information, please contact the theme supervisor G. Trinkūnas.