Department of Materials Science and Engineering, Yonsei University , Seoul 03722, Korea.
ACS Appl Mater Interfaces. 2017 Jun 28;9(25):21382-21389. doi: 10.1021/acsami.7b04728. Epub 2017 Jun 15.
Black phosphorus (BP) has attracted significant attention due to its excellent optical and electrical properties. However, the rapid degradation of BP under ambient air limits further research on its properties and implementation in various fields. This degrading behavior lowers the performance of BP-based devices and can even result in a complete failure when exposed to air for an extended period of time. In our research, the degraded surface with "bubbles" was recovered to its pristine state by rinsing with deionized water and following with post-treatments. The formation of bubbles and their optical, morphological, and electrical effects were systematically investigated by fabricating BP field-effect transistors (FETs) in conjunction with micro-Raman spectroscopy and atomic force microscopy. Water rinsing of the degraded BP flakes also allowed us to thin BP flakes down because phosphorus atoms are consumed while forming bubbles. Therefore, recovery of the pristine surface not only results in a smoother and thinner morphology but also improves device performances. After the rinsing process, field-effect mobility of the BP FET was maintained, whereas a significant enhancement in the switching behaviors was achieved in conclusion. The capability of reversing the inevitable degradation that occurs once exposed to ambient conditions can open up new opportunities for further applications of BP that was limited due to its instability.
黑磷（BP）由于其优异的光学和电学性能而引起了广泛关注。然而，BP 在环境空气中的快速降解限制了对其性质的进一步研究及其在各个领域的应用。这种降解行为降低了基于 BP 的器件的性能，并且当长时间暴露于空气中时甚至可能导致完全失效。在我们的研究中，通过用去离子水冲洗和随后的后处理，将具有“气泡”的降解表面恢复到原始状态。通过结合微拉曼光谱和原子力显微镜来制造 BP 场效应晶体管（FET），系统地研究了气泡的形成及其光学、形态和电学效应。退化的 BP 薄片的水冲洗也允许我们将 BP 薄片变薄，因为在形成气泡时消耗了磷原子。因此，原始表面的恢复不仅导致更光滑和更薄的形态，而且还改善了器件性能。在冲洗过程之后，BP FET 的场效应迁移率得以维持，而在结论中，开关行为得到了显著增强。这种能够逆转一旦暴露于环境条件就会发生的不可避免的降解的能力，为进一步应用 BP 开辟了新的机会，因为 BP 的不稳定性限制了其应用。
