铜箔碳掺杂对化学气相沉积生长的六方氮化硼中含碳色心的高效制备及其调控

缺陷和掺杂对材料的力学、 电子和光学性能均具有重要影响. 六方氮化硼(Hexagonal Boron Nitride, hBN)由于具有a6 eV 的宽带隙, 其中的点缺陷可以在带隙内产生发射波长覆盖近紫外-近红外波段的室温稳定发光的深能级色心, 是量子光源等光学的理想载体. 近年来的实验和理论研究表明, 碳缺陷是h-BN 可见光波段单光子发射的主要可能来源之一; 然而, 当前对h-BN 中碳缺陷的有效制备和精确调控仍存在挑战. 本文报道了一种有效方法, 通过在化学气相沉积(Chemicalvapordeposition, CVD) 过程中预先控制用于催化生长h-BN 的铜箔衬底中的碳含量, 制备得到了不同密度的零声子发射(Zero-phononlines, ZPL)波长位于626±3 nm 的色心; 此外, 我们还观察到气氛退火对色心发光显著的调控作用. 该色心优良的单色性和可调控性有助于推动基于h-BN 的量子光源和光子学器件的潜在应用, 对理解h-BN 中碳缺陷的形成亦具有重要意义.

Highly-Effective Preparation and Control of the Carbon-Related Color Centers in CVD-Grown h-BN through Carbon-Doped Copper Foils

Defects and doping have significant impacts on the mechanical, electronic, and optical properties of materials. Thanks to wide bandgap of ~6 eV, various point defects in two-dimensional (2D) hexagonal boron nitride (h-BN) can form deep-level color centers within the band gap allowing stable room-temperature emissions covering the near-ultraviolet (UV) to visible spectral range, and therefore having been regarded as an ideal candidate for 2D photonics devices such as quantum light sources. Both recent experimental and theoretical studies have shown that carbon defects are one of the main possible sources of visible-range single photon emission (SPE) of h-BN. However, effective preparation and precise control of carbon defects in 2D h-BN remain challenges. In this paper, we report an efficient method to prepare density-controlled color center whose zero-phonon line (ZPL) locates at 626 ± 3 nm, through pre-doping the carbon content into copper foil substrates for the catalytic chemical vapor deposition (CVD) growth of h-BN. Furthermore, post-annealing can also significantly enhance and tune this color center emission. The excellent monochromaticity and controllability of this color center will help promote the potential application of h-BN-based quantum light sources and photonics devices, the results also have significance for understanding the formation mechanism of carbon-containing defects in h-BN.