Project Summary

Envision a world where solar cells are placed on the hoods of every car, on the tiles of every roof, and even implemented into electricity-generating layers in flak jackets for every one of our soldiers in the Middle East. Organic solar cells, also known as organic photovoltaic (OPV) devices, present these possibilities. Unlike currently produced silicon-based solar cells that are costly to make, rigid, and fragile, OPV devices are made from abundant organic materials, are flexible and highly durable, and most importantly are low-cost—they can be printed onto large surfaces in a similar process to newspaper. 

My project focused on the molecule lead phthalocyanine (abbreviated PbPc) paired with carbon fullerene (C60) in organic photovoltaic devices. I looked at three different OPV architectures—planar, mixed, and graded—to find which one produced the highest efficiency. My two goals were to produce an OPV device that absorbed in the near-infrared spectrum and to find which of my three architectures produced the highest efficiency for this material combination.

After testing varying composition ratios of mixed OPV devices and varying thicknesses of both planar and graded OPV devices, I found that a mixed cell with a 1:1 ratio of PbPc to C60 produced the highest efficiency of all my devices, with an efficiency of 0.58 %. However, I then found a study by Rand et al. (2005) that suggested adding another layer of copper phthalocyanine (CuPc) into the OPV device would further increase efficiency. After adding this secondary layer to my most efficient graded cell, most efficient mixed cell, and three planar cells (to replicate the Rand study), I found that my planar-architecture cell engineered with 100-Å CuPc, 100-Å PbPc, and 350-Å C60 produced the highest efficiency of all my cells with an efficiency of 1.54%. This cell that I engineered set an efficiency record, surpassing efficiencies of all other cells engineered from similar materials.

Google Science Fair Presentation