High Efficiency Organic Solar Cells with Novel Transparent Electrodes

North Carolina State University, Raleigh NC

Investigators

Abstract

High Efficiency Organic Solar Cells with Novel Transparent Electrodes (ECCS-0653722) North Carolina State University (J. Narayan, PI) Project Summary The primary objective of this research is to find novel transparent electrode materials for organic solar cells, alternative to indium tin oxide which is used presently as a transparent electrode. The ITO, which has been used as TCO (transparent conducting oxide) for a long time, poses a serious problem due to its high cost, limited supply, and poor chemical stability and diffusion barrier properties. Intellectual Merit: This proposal addresses novel molybdenum oxide (MoOx doped with Mn) and zinc oxide (ZnO doped with Ga or Al) based materials as alternative to ITO. The MoOx( 2< x<3) could be potentially better than ZnO-based materials in view of its higher work function. The proposed research has four components: (1) Synthesis and processing ZnO (doped with Ga or Al) and MoOx( 2< x<3) films on glass, and sapphire (0001) where these films cab be grown as epitaxial single crystal via domain matching epitaxy. The grain size and the nature of grain boundaries will be varied systematically to establish microstructure-electrical property correlations; (2) Establish resistivity versus temperature correlations for various microstructures ranging from random poly, to textured poly, to single crystals; (3) Study the properties of defects and interfaces and correlate this information with solar cell efficiency; and (4) Fabricate high-efficiency solar cells utilizing TCO films of optimized microstructures and properties. Broader Impacts: The proposal includes training of graduate and undergraduate students and collaborations with NC A&T University to attract minority students into the graduate program at NCSU. The outreach will also involve ASM-International sponsored Summer School for rising High-School seniors. These students are exposed to recent developments in new materials, analysis tools, materials properties and modeling. The PI teaches a series of courses through distance-education network, where students from NC A&T can take courses and learn latest developments in novel materials, processing, characterization and modeling, and device fabrication.