Date of Award

1-1-2011

Degree Name

Doctor of Philosophy

Department

Physics

First Advisor

Dr. Clement Burns

Abstract

Organic materials are of great interest for use as low cost electronic and optoelectronic devices. However, the performance of organic solar cells is inferior to the performance of inorganic solar cells. There are many factors that affect the quality of the organic solar cells performance including; the absorption-spectrum bandwidth of organic materials is narrower than the solar spectrum, and when sunlight is absorbed a strongly bond electron and hole pair (exciton) is produced. The exciton forms due to the low dielectric constant and the large effective masses. The aim of this research is to improve the performance of these organic solar cells. In the first part of this work, we try to expand the absorption-spectrum bandwidth for the organic materials in the visible spectrum region by varying the band gap. Different sizes of copper phthalocyanine (CuPc) nanoparticles were synthesized to study a shift in the absorption energy as the particles become smaller. In the second part, we try to directly generate free electrons and holes by using organic semiconductor materials with high dielectric constants. Copper phthalocyanine oligomer, which has a high dielectric constant, was used as an active layer (donor) in the organic solar cells to allow the exciton to break. The results show that copper phthalocyanine (CuPc) nanoparticles did not achieve a large shift in the peak positions of the visible spectrum; however, this technique might work for other organic materials. Organic solar cells containing a layer of copper phthalocyanine oligomer show improvement in the lifetime and stability.

Access Setting

Dissertation-Open Access

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