This process provides for the large-scale fabrication of zinc oxide (ZnO) nanowires—components that are important for commercial applications like energy harvesting, sensing, optoelectronics, and electronics. In this method, a photoresist layer is exposed to a coherent light interference pattern that includes periodically and alternately spaced dark bands and light bands along a first orientation. The substrate is then rotated to expose it to the same interference pattern at a transverse orientation. This creates an array of ordered holes in the photoresist layer where nanowires can grow uniformly.
This Georgia Tech ZnO nanowire framework can be used to develop high-efficiency solar cells that collect solar and mechanical energy simultaneously. By wrapping the n-type ZnO nanowires with p-type polymers to form a p-n junction—the interface of two semiconductor materials—the cell relies on the photovoltaic effect to harvest solar energy. A piezoelectric nanogenerator is built by placing an electrode on the nanowires to collect mechanical energy from the device’s environment.
- Low cost: Simplifies the process for fabricating ZnO nanowires in order for the technology to be industrially viable
- Powerful: Produces a large number of nanowires efficiently for high throughput power generation
- Innovative: Streamlines environmental energy harvesting by collecting both solar and mechanical energy with the same device
- Solar cells
- Ultraviolet (UV) and other types of sensors
- Light-emitting diode (LED) efficiency
- Energy harvesting
- Electronics and optoelectronics
Assembly and integration of highly ordered nanowire arrays at large scales are important for multi-functional devices and systems. None of the current approaches, however, provides a reliable, high-throughput, and low-cost solution for the fabrication of patterned ZnO nanowire arrays at the high level that is required for industrial viability. This Georgia Tech fabrication method overcomes the challenges of scaling this nanowire production and also offers application in a unique, integrated, high-efficiency solar cell. The demand for more advanced energy harvesting technologies will continue to increase as the world’s long-term renewable power generation needs grow.