Hayee Fariah, Yu Leo, Zhang Jingyuan Linda, Ciccarino Christopher J, Nguyen Minh, Marshall Ann F, Aharonovich Igor, Vučković Jelena, Narang Prineha, Heinz Tony F, Dionne Jennifer A
Department of Electrical Engineering, Stanford University, Stanford, CA, USA.
Department of Applied Physics, Stanford University, Stanford, CA, USA.
Nat Mater. 2020 May;19(5):534-539. doi: 10.1038/s41563-020-0616-9. Epub 2020 Feb 24.
Defects in hexagonal boron nitride (hBN) exhibit high-brightness, room-temperature quantum emission, but their large spectral variability and unknown local structure challenge their technological utility. Here, we directly correlate hBN quantum emission with local strain using a combination of photoluminescence (PL), cathodoluminescence (CL) and nanobeam electron diffraction. Across 40 emitters, we observe zero phonon lines (ZPLs) in PL and CL ranging from 540 to 720 nm. CL mapping reveals that multiple defects and distinct defect species located within an optically diffraction-limited region can each contribute to the observed PL spectra. Local strain maps indicate that strain is not required to activate the emitters and is not solely responsible for the observed ZPL spectral range. Instead, at least four distinct defect classes are responsible for the observed emission range, and all four classes are stable upon both optical and electron illumination. Our results provide a foundation for future atomic-scale optical characterization of colour centres.
六方氮化硼（hBN）中的缺陷表现出高亮度、室温量子发射，但其较大的光谱变异性和未知的局部结构对其技术应用构成挑战。在这里，我们结合光致发光（PL）、阴极发光（CL）和纳米束电子衍射，直接将hBN量子发射与局部应变相关联。在40个发射体中，我们在PL和CL中观察到零声子线（ZPL），范围从540到720nm。CL映射显示，位于光学衍射极限区域内的多个缺陷和不同的缺陷种类都可以对观察到的PL光谱做出贡献。局部应变图表明，激活发射体不需要应变，并且应变并非是观察到的ZPL光谱范围的唯一原因。相反，至少有四类不同的缺陷导致了观察到的发射范围，并且这四类缺陷在光学和电子照射下都是稳定的。我们的结果为未来色心的原子尺度光学表征奠定了基础。
