Diamond nanowires embedded with platinum nanoparticles are set to revolutionize high-temperature solar-blind photodetection with their remarkable performance and stability. Despite the excellent properties of diamond as an ultrawide-bandgap semiconductor material for solar-blind UV photodetectors, its application has been limited by low photoresponsivity at high temperatures due to surface oxygen termination. Now, researchers from the University of Science and Technology of China, Shenyang National Laboratory for Materials Science, and other institutions, led by professor Dongming Sun, have made a significant breakthrough. Their latest study presents a novel approach to fabricating high-performance photodetectors using single-crystal diamond nanowires (DNWs) embedded with platinum (Pt) nanoparticles.

Why Platinum-Embedded Diamond Nanowires Matter

• Enhanced Responsivity: The Pt-embedded DNWs achieve a responsivity of 68.5 A W^-1 under 220 nm illumination at room temperature, which is approximately 2000 times higher than that of oxygen-terminated bulk diamond devices. Notably, the responsivity further increases with temperature, reaching an exceptional value of 3098.7 A W^-1 at 275 °C.
• Excellent Spectral Selectivity: The Pt-embedded DNWs maintain high spectral selectivity, with a UV/visible rejection ratio of 550 at room temperature and 4303 at 275 °C, making them highly suitable for solar-blind UV detection.
• Improved Stability: The devices exhibit stable and reproducible response characteristics even at elevated temperatures, demonstrating long-term performance stability after undergoing 24-hour thermal treatment at 275 °C and maintaining functionality after three months of atmospheric storage.

Innovative Fabrication and Mechanisms

• Unique Fabrication Process: The Pt-embedded DNWs were fabricated through a four-step process involving the preparation of original DNWs, deposition of Pt films, dewetting of Pt films into nanoparticles, and diamond homoepitaxial growth. This process ensures the uniform embedding of Pt nanoparticles within the DNWs while maintaining their single-crystal structure.
• Synergistic Enhancement Mechanisms: The outstanding performance of the Pt-embedded DNWs can be attributed to multiple factors working together. The one-dimensional nanowire structure provides efficient carrier transport channels. Deep-level defects within the diamond lattice contribute to carrier generation. The localized surface plasmon resonance (LSPR) effect induced by the embedded Pt nanoparticles enhances light absorption. Additionally, the localized Schottky junctions at the Pt/diamond interface facilitate efficient carrier separation.

Future Outlook

• Optimization and Application: Future research may focus on further optimizing the size and distribution of Pt nanoparticles to maximize performance. The Pt-embedded DNWs hold great potential for practical applications in harsh environments such as aerospace, industrial monitoring, and defense systems, where high-temperature stability and reliable solar-blind UV detection are crucial.
• Material Exploration: Exploring other metal nanoparticles or composite structures could lead to new opportunities for enhancing the performance of diamond-based photodetectors. Additionally, integrating these advanced materials with flexible or wearable technologies could expand their application scope.

Stay tuned for more exciting developments from this research team as they continue to push the boundaries of high-performance photodetection technology!