Design and Fabrication of a Gallium Phosphide Nanowire Betavoltaic Device

Abstract

Betavoltaic (BV) devices, which convert beta particle radiation into electrical power, represent a promising solution for long-term energy generation in environments where traditional low power sources are impractical. While BV technology has been studied for over fifty years, its development has been limited, particularly in the emerging field of III-V semiconductor nanowire (NW) implementations. This dissertation advances both the theoretical understanding and practical development of gallium phosphide (GaP) NW-based BV generators, with a specific focus on overcoming geometric constraints that impact device performance.

Through comprehensive modeling and experimental validation, this work establishes fundamental relationships between NW architecture, material properties, and energy conversion efficiency. The research presents novel insights into optimizing carrier transport and radiation absorption through precise control of NW geometry and material interactions. New processing techniques for fabricating tailored GaP NW arrays are developed and demonstrated, enabling enhanced BV performance through improved charge collection efficiency.

The findings bridge critical gaps in current understanding of radiation-driven energy conversion in nanostructured materials, while providing practical solutions to long-standing challenges in BV device design. This work establishes a foundation for developing high-efficiency BV power sources, with potential applications in space exploration, medical implants, and remote sensing systems. The theoretical framework and fabrication methodologies presented here open new pathways for advancing BV technology toward practical implementation.