Department of Electronic Engineering, Tohoku University , Aoba 6-6-05, Aramaki, Aoba-Ku, Sendai, Japan.
ACS Nano. 2014 Dec 23;8(12):12777-85. doi: 10.1021/nn5059858. Epub 2014 Dec 5.
A photoluminescence (PL) peak has been observed from a monolayer of transition metal dichalcogenide (TMD), which is known to be an ideal 2D semiconductor. The PL peak appears near the low-energy side of neutral free excitons with very sharp peak width (∼10 meV) at low temperature (83 K). Systematic temperature-dependent PL measurements reveal that the peak can be explained by bound excitons being trapped by the surface impurities, which results in a highly localized state for the excitons. Since the optically detectable, highly localized impurity state promises to have extensive practical applications for quantum optics, our finding represents an important step in the study of 2D materials for use in quantum computation and information.
单层过渡金属二卤族化合物（TMD）中观察到光致发光（PL）峰，TMD 是众所周知的理想二维半导体。PL 峰出现在中性自由激子的低能侧附近，在低温（83 K）下具有非常尖锐的峰宽（约 10 meV）。系统的温度依赖 PL 测量表明，该峰可以用被表面杂质捕获的束缚激子来解释，这导致激子处于高度局域化的状态。由于光学可检测的、高度局域化的杂质态有望在量子光学中有广泛的实际应用，我们的发现代表了用于量子计算和信息的二维材料研究的重要一步。
