Organic Solar Cells: Construction and Characterization

An Organic Solar Cell is a type of photovoltaic cell that uses organic polymers for light absorption and charge transport. Organic Solar Cells have benefits such as being light weight, flexible, conforming to variety of surfaces, and potentially inexpensive and disposable. Different polymers are used in these cells to alter the band gap and utilize different parts of the solar spectrum. Structure can vary in the sequence of the layers, such as the cells being regular or inverted cells. We will present results on regular cells with hole injection layers PEDOT:PSS and PLEXCore, and active layers of P3HT, PCPDTBT, and PCBM (C-60). The interaction of the HIL with the solvent of the subsequent polymer blend solution was studied, as well as other aspects of solution deposition. We show that if this process is not well controlled substantial electrical shorts form in the device deteriorating the photovoltaic performance. Methods of characterization include Current-Voltage characteristics and Impedance spectroscopy, which give a great insight on the electrical processes in the devices. Understanding all the parameters and characterizations of the devices allows us to improve and achieve reproducibility in the devices.