Hot electrons in a nanowire hard X-ray detector

• Published in: Nature communications Vol. 11; no. 1; p. 4729
• Main Authors: Zapf, Maximilian, Ritzer, Maurizio, Liborius, Lisa, Johannes, Andreas, Hafermann, Martin, Schönherr, Sven, Segura-Ruiz, Jaime, Martínez-Criado, Gema, Prost, Werner, Ronning, Carsten
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 18.09.2020; Nature Publishing Group UK; Nature Portfolio
• Subjects: Physics; TRANSPORT; SOLAR-CELLS; SI; MONTE-CARLO ANALYSIS; THERMAL-CONDUCTIVITY; LOCAL-STRUCTURE; GAAS
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-18384-x

Nanowire chip-based electrical and optical devices such as biochemical sensors, physical detectors, or light emitters combine outstanding functionality with a small footprint, reducing expensive material and energy consumption. The core functionality of many nanowire-based devices is embedded in their p-n junctions. To fully unleash their potential, such nanowire-based devices require - besides a high performance - stability and reliability. Here, we report on an axial p-n junction GaAs nanowire X-ray detector that enables ultra-high spatial resolution (~200 nm) compared to micron scale conventional ones. In-operando X-ray analytical techniques based on a focused synchrotron X-ray nanobeam allow probing the internal electrical field and observing hot electron effects at the nanoscale. Finally, we study device stability and find a selective hot electron induced oxidization in the n-doped segment of the p-n junction. Our findings demonstrate capabilities and limitations of p-n junction nanowires, providing insight for further improvement and eventual integration into on-chip devices.