Sharp zero-phonon lines of single organic molecules on a hexagonal boron-nitride surface - dataset

Single fluorescent molecules embedded in the bulk of host crystals have proven to be sensitive probes of the dynamics in their nano environment, thanks to their narrow (about 30-50 MHz or 0.1-0.2 μeV) optical linewidth of the 0-0 zero‑phonon line (0-0 ZPL) at cryogenic temperatures. However, the optical linewidths of the 0-0 ZPL have been found to increase dramatically as the single molecules are located closer to a surface or interface, while no 0-0 ZPL has been detected for single molecules on any surface. Here we study single terrylene molecules adsorbed on the surface of hexagonal boron-nitride (hBN) substrates. Our low-temperature results show that it is possible to observe the 0-0 ZPL of fluorescent molecules on a surface. We compare our results for molecules deposited on the surfaces of annealed and non-annealed hBN flakes and we see a marked improvement in the spectral stability of the emitters after annealing.

嵌入主体晶体本体中的单荧光分子已被证实是其纳米环境动力学的灵敏探针，这得益于其在低温下0-0声子零线（0-0 ZPL）的窄光学线宽（约30~50 MHz或0.1~0.2 μeV）。然而，研究发现，当单分子愈发靠近表面或界面时，其0-0 ZPL的光学线宽会显著增宽，且从未在任何表面上的单分子中检测到0-0 ZPL信号。本文针对吸附于六方氮化硼（hBN）衬底表面的单苝烯（terrylene）分子展开研究。我们的低温实验结果表明，在表面附着的荧光分子中观测到0-0 ZPL信号是可行的。我们对比了分子沉积在退火与未退火hBN薄片表面的实验结果，发现经退火处理后，该类发光体的光谱稳定性得到了显著提升。