Date of Award
5-2016
Major
Chemistry
Faculty Advisor
Wang, Lichang
Abstract
The global energy consumption is expected to double by 2050. Therefore, alternative energy sources such as solar power will have to be utilized. This work seeks to improve next generation solar cells, namely organic solar cells (OSCs) and dye-sensitized semiconductor solar cells (DSSCs), using theoretical and experimental approaches. Computational studies were done on electron acceptor and electron donor molecules that have potential use in OSCs and DSSCs. An improved Density Functional Theory (DFT) method that better represents experimental cyclic voltammetry was developed to predict the electronic properties of these molecules. The electronic data of the electron acceptor molecules were used to design OSCs by matching cascading HOMO and LUMO energy levels with a known donor molecule. Absorption spectra were generated using Time-Dependent DFT (TD-DFT) calculations. The effect of functional group on the accuracy of DFT and TD-DFT calculations was also studied in electron donor molecules. It was found that the prediction accuracy of the electronic properties increases as the electron withdrawing ability of the functional group increases, while the accuracy of the predicted absorption spectra decreases as the electron withdrawing ability of the functional group increases. OSCs and DSSCs were fabricated using coal dye solutions as a photosensitizer. The electrical output of these solar cells was tested and the efficiency of each solar cell device was calculated. It was found that the use of coal gave significantly better results than the blank. Therefore, coal dye solutions can be utilized as potential photosensitizers in these devices.