Tyler J. Perlenfein
Advisor: Jason Baxter
Abstract:
The field of organic photovoltaics has been growing rapidly for more than a
decade. With the low materials and processing costs, high materials usage and
scalability, and flexible applications, the plastic solar cell is on the cusp of
economic feasibility. To make this type of cell more attractive, the module
efficiency and lifetime must be improved by a significant margin. In this work, the
essential materials of an organic solar cell are explored by physical
experimentation. Through systematic parameter studies, the photoactive layer of
the cell is optimized for thickness and annealing conditions while the hole and
electron transport layers are optimized for ease of deposition and contribution to
overall cell performance. More advanced techniques for characterization are
discussed, including an introduction to electrochemical impedance spectroscopy
and a demonstration of how the quantum efficiencies of a cell can be measured.
All experiments and discussion are conducted with the ultimate goal of increasing
the efficiency of the organic solar cell. The most efficient cells produced in this
work fall in the 3.1 - 3.3 % range, with Jsc of 10 - 11 mA/cm2 and Voc of 540 mV.
These air-stable cells used an inverted architecture consisting of an
ITO/TiOx/P3HT:PCBM/MoO3/Ag stack.