Charge Transfer Dynamics within Porphyrin Graphene Quantum Dot Systems Significance in Sensing and Dye Sensitized Solar Cell Applications

Abstract

Porphyrins are the innocuous organic molecules that have been newlinewidely studied from ancient times onward. They are the macrocyclic and newlineheterocyclic compounds that are inevitable part of most of the important newlinebiological molecules. The characteristic structure of porphyrin, known as newlinethe porphine ring , includes four pyrrole units connected through methine newlinebridges between the and#945;-carbons of nearby pyrrole rings which forms the newlineplanar, cyclic structure of the porphyrin ring. The feasibility of several newlinestructural modifications on this ring is due to the availability of 4 meso newlineand 8 and#946; positions and the difference in their substitutions results in a newlinevariety of molecules with contrasting properties. In common, porphyrin newlinemolecules have their own assets such as long range absorption, structural newlinerigidity, high extinction coefficients, feasibility for peripheral and core newlinesubstitutions, high thermal and photostability. newlineIn parallel, GQDs are the newly discovered carbon based nanomaterial newlinewhich gained wide attention of the scientific society on account of its special newlineadvantages such as low toxicity, tunable photoluminescence, robust chemical newlineinertness, high stability, excellent water solubility, profuse surface newlinemodifications, bio-compatibility, high transparency, surface area, electrical newlineand thermal conductivity as compared to the conventional inorganic newlinesemiconductor quantum dots and other organic fluorophores. They have newlinetriggered enormous scientific interest as a unique fluorescent material newlinefrom the carbon nano-family due to these outstanding characteristics and newlineapplication possibilities. The complete characterization of both GQDs and newlineporphyrins are based on analytical and spectral data. newline