Interaction between alkali metals and diamond: Etching and charge states of NV centers. (September 2021)

• Record Type: Journal Article
• Authors: Takehana, Hiroki; Yamane, Ichiro; Yanase, Takashi; Nagahama, Taro; Shimada, Toshihiro
• Is Part Of: Carbon. Volume 182(2021)
• Page Start: 585
• Page End: 592
• Publication Date: 2021-09
• Subjects: Diamond -- Alkali metals -- NV center -- Etching -- Band bending; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2021.06.059
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Single crystal diamond particles were heated with liquid phase alkali metals (Li, Na, K) in an argon atmosphere. It was found that Li reacts with the diamond above 600 °C, Na makes the surface rougher on a nm scale at 800 °C, and K did not change the surface morphology. The etching speed by the reaction with Li is the fastest on the (001) surface. Photoluminescence of the NV- (negatively charged nitrogen-vacancy) center decreased only after the annealing with K. DFT calculations explained the strong chemical interaction between Li and the diamond (001) surfaces, and upward band bending at the interfaces with Na and K. The behavior of the NV- center photoluminescence is consistent with the extent of band bending. Graphical abstract: Image 1 Highlights: Diamond crystals were annealed in high temperature alkali metal liquids. Etching was observed in Li, in which (001) surface was strongly etched. NV − center seems to lose their electrons only by annealing in K. DFT calculation revealed upward band bending is strongest in K.