Engineering scalable device architectures for lead sulfide quantum dot solar cells

Abstract

In recent years flexible and lightweight solar cell technologies have emerged as complements to silicon solar panels in the rapidly growing clean energy industry. As one of these new technologies, quantum dot solar cells have shown remarkable shelf life stability with increasingly competitive power conversion efficiencies, yet remain very expensive to manufacture. Some of these production costs are due to expensive materials used in the quantum dot solar cell device stack, namely gold electrodes. While gold cannot be used on a commercial scale, there are less expensive but more chemically reactive materials that can be used. Replacing gold with aluminum or copper in quantum dot solar cells would cut material costs by a factor of 12,000. In this work, I develop a new quantum dot solar cell architecture that maintains power conversion efficiency while dramatically reducing the electrode material costs. The electrical and optical properties of a nickel oxide film are developed for a new hole-transporting buffer layer as I determine how deposition conditions impact the sputtered film. I integrate the sputtered nickel oxide film into a new quantum dot solar cell architecture that enables aluminum or copper electrodes to be used instead of gold. Finally, I characterize the storage stability of the proposed architecture and investigate strategies for enhancing stability of devices containing chemically reactive top electrodes. By improving the storage stability of the new architecture, efficient quantum dot solar cells move closer to the production line.