Comparison of optical and photovoltaic characteristics of solar cells based on hetero-junctions of organic nanocomposite films on Si and GaAs

Comparison between solar cell heterostructures based on poly(3,4-ethylenedioxythiophene)-poly(styrene-sulfonate) (PEDOT:PSS) organic complex thin film and semiconductors (Si, GaAs) with flat and microrelief interfaces have been performed. PEDOT:PSS film thicknesses and optical parameters were ascertained using spectroscopic ellipsometry, while electrical dc-conductivity was determined using the four-point probe method. A method of increasing the conductivity of PEDOT:PSS films by forming a multilayer film with a decreased content of PSS component is proposed. Plasmon-active metal nanoparticles (Au, Ag) have been grown on the active interface region to increase photoconversion efficiency. They reduce the structure series resistance and increase the I–V characteristic fill factor as well as the incident light absorption. The post-processing treatment method of fabricated structures to obtain a tunnel-thin intermediate layer of SiO2 of optimal thickness has been proposed. The photoelectric properties of the fabricated solar cells have shown that GaAs-based structures have more stable long-term characteristics and higher open-circuit voltage than Si-based ones.