SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, Shenzhen University , Shenzhen 518060, China.
Department of Chemistry, National University of Singapore , Singapore 117543, Singapore.
Nano Lett. 2017 Jul 12;17(7):4122-4129. doi: 10.1021/acs.nanolett.7b00903. Epub 2017 Jun 22.
Two-dimensional black phosphorus configured field-effect transistor devices generally show a hole-dominated ambipolar transport characteristic, thereby limiting its applications in complementary electronics. Herein, we demonstrate an effective surface functionalization scheme on few-layer black phosphorus, through in situ surface modification with potassium, with a view toward high performance complementary device applications. Potassium induces a giant electron doping effect on black phosphorus along with a clear bandgap reduction, which is further corroborated by in situ photoelectron spectroscopy characterizations. The electron mobility of black phosphorus is significantly enhanced to 262 (377) cm V s by over 1 order of magnitude after potassium modification for two-terminal (four-terminal) measurements. Using lithography technique, a spatially controlled potassium doping technique is developed to establish high-performance complementary devices on a single black phosphorus nanosheet, for example, the p-n homojunction-based diode achieves a near-unity ideality factor of 1.007 with an on/off ratio of ∼10. Our findings coupled with the tunable nature of in situ modification scheme enable black phosphorus as a promising candidate for further complementary electronics.
二维黑磷配置的场效应晶体管器件通常表现出空穴主导的双极性输运特性，从而限制了其在互补电子学中的应用。在此，我们通过与钾的原位表面改性，展示了一种对少层黑磷的有效表面功能化方案，以期实现高性能互补器件应用。钾对黑磷产生了巨大的电子掺杂效应，同时明显减小了带隙，这进一步通过原位光电子能谱表征得到了证实。通过钾修饰，黑磷的电子迁移率在两端（四端）测量中分别显著提高到 262（377）cm V s，提高了 1 个数量级以上。利用光刻技术，开发了一种空间可控的钾掺杂技术，在单个黑磷纳米片上建立高性能互补器件，例如，基于 p-n 同质结的二极管实现了近 1 的理想因子，开关比约为 10。我们的研究结果以及原位修饰方案的可调特性，使黑磷成为进一步互补电子学的有前途的候选材料。
