Super-Stable High-Quality Few-Layer Black Phosphorus for Photonic Applications
Super-Stable High-Quality Few-Layer Black Phosphorus for Photonic Applications
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DOI：
10.1021/acsanm.1c00351
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发表时间：
2021-04-20
影响因子：
5.9
通讯作者：
Ning, Cun-Zheng
中科院分区：
文献类型：
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作者：
Li, Dongying;Yu, Yueyang;Ning, Cun-Zheng
低层黑磷（BP）由于其具有强烈的层依赖性的量子化能带结构，从而具有波长可调的发射和吸收特性，是最重要的二维材料之一。这种特性对于各种光子器件的应用，如激光器、探测器和宽范围近红外波长的调制器是必不可少的。然而，材料的质量和稳定性已经成为瓶颈，同时还有其他挑战，如较差的发光性能和材料基本参数的相当大的不确定性。在本文中，我们开发了一种系统的策略，通过结合O-2等离子体蚀刻，氮化硼夹层和随后的热退火来制备高质量稳定的少层BP样品。我们的策略已经成功地生产了几层BP样品，具有创纪录的长寿命，7个月后光致发光强度仍保持80%。重要的是，我们发现氧化BP表面的晶格重建和修复使BP厚度增加了一层，从而恢复了BP的晶体结构，提高了材料的质量和稳定性，并恢复了其固有的光学性质。结果，实现了200x的PL增强和2x的线宽减小，从而首次建立了层数和PL能量之间更明确的关系。我们的研究结果可以帮助释放出在近红外波长范围内的光子学应用中少层BP的全部潜力。
Few-layer black phosphorus (BP) is one of the most important 2D materials due to its strongly layer-dependent quantized band structure, which leads to wavelength tunable emission and absorption properties. Such properties are essential for a variety of photonic device applications such as lasers, detectors, and modulators in a wide range of near-infrared wavelengths. However, the material quality and stability have become a bottleneck along with other challenges such as poor light emission properties and considerable uncertainty of basic material parameters. In this paper, we developed a systematic strategy for preparing high-quality stable few-layer BP samples by combining O-2 plasma etching, boron nitride sandwiching, and subsequent thermal annealing. Our strategy has successfully produced few-layer BP samples with a record-long lifetime, with 80% of photoluminescence intensity remaining after 7 months. Importantly, we found that lattice reconstruction and reparation of oxidized BP surfaces increased BP thickness by one monolayer, leading to the restoration of BP crystal structure, improved material quality and stability, and restoration of intrinsic optical properties. As a result, 200x PL enhancement and 2x line width reduction are achieved, allowing the establishment of a more definite relationship between the layer number and PL energies for the first time. Our results could help unleash the full potential of few-layer BP in photonics applications in a wide range of near-infrared wavelengths.