Han Kyu Seok, Kalode Pranav Y, Koo Lee Yong-Eun, Kim Hongbum, Lee Lynn, Sung Myung Mo
Department of Chemistry, Hanyang University, Seoul, Republic of Korea.
Nanoscale. 2016 Mar 7;8(9):5000-5. doi: 10.1039/c5nr08016a.
Graphene applications require high precision control of the Fermi level and carrier concentration via a nondestructive doping method. Here, we develop an effective n-doping technique using atomic layer deposition (ALD) of ZnO thin films on graphene through a reactive molecular layer. This ALD doping method is nondestructive, simple, and precise. The ZnO thin films on graphene are uniform, conformal, of good quality with a low density of pinholes, and finely tunable in thickness with 1 Å resolution. We demonstrate graphene transistor control in terms of the Dirac point, carrier density, and doping state as a function of the ZnO thickness. Moreover, ZnO functions as an effective thin-film barrier against air-borne water and oxygen on the graphene, resulting in extraordinary stability in air for graphene devices. ZnO ALD was also applied to other two-dimensional materials including MoS2 and WSe2, which substantially enhanced electron mobility.
石墨烯应用需要通过无损掺杂方法对费米能级和载流子浓度进行高精度控制。在此，我们通过反应性分子层在石墨烯上采用原子层沉积（ALD）氧化锌薄膜，开发出一种有效的n型掺杂技术。这种ALD掺杂方法无损、简单且精确。石墨烯上的氧化锌薄膜均匀、保形、质量良好且针孔密度低，并且厚度可通过1 Å分辨率进行精细调节。我们展示了作为氧化锌厚度函数的狄拉克点、载流子密度和掺杂状态方面的石墨烯晶体管控制。此外，氧化锌在石墨烯上充当了有效的薄膜屏障，可抵御空气中的水和氧气，从而使石墨烯器件在空气中具有非凡的稳定性。氧化锌ALD还应用于包括二硫化钼和二硒化钨在内的其他二维材料，这显著提高了电子迁移率。
