Kozhakhmetov Azimkhan, Schuler Bruno, Tan Anne Marie Z, Cochrane Katherine A, Nasr Joseph R, El-Sherif Hesham, Bansal Anushka, Vera Alex, Bojan Vincent, Redwing Joan M, Bassim Nabil, Das Saptarshi, Hennig Richard G, Weber-Bargioni Alexander, Robinson Joshua A
Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
Adv Mater. 2020 Dec;32(50):e2005159. doi: 10.1002/adma.202005159. Epub 2020 Nov 9.
Reliable, controlled doping of 2D transition metal dichalcogenides will enable the realization of next-generation electronic, logic-memory, and magnetic devices based on these materials. However, to date, accurate control over dopant concentration and scalability of the process remains a challenge. Here, a systematic study of scalable in situ doping of fully coalesced 2D WSe films with Re atoms via metal-organic chemical vapor deposition is reported. Dopant concentrations are uniformly distributed over the substrate surface, with precisely controlled concentrations down to <0.001% Re achieved by tuning the precursor partial pressure. Moreover, the impact of doping on morphological, chemical, optical, and electronic properties of WSe is elucidated with detailed experimental and theoretical examinations, confirming that the substitutional doping of Re at the W site leads to n-type behavior of WSe . Transport characteristics of fabricated back-gated field-effect-transistors are directly correlated to the dopant concentration, with degrading device performances for doping concentrations exceeding 1% of Re. The study demonstrates a viable approach to introducing true dopant-level impurities with high precision, which can be scaled up to batch production for applications beyond digital electronics.
对二维过渡金属二硫属化物进行可靠、可控的掺杂，将有助于实现基于这些材料的下一代电子、逻辑存储和磁性器件。然而，迄今为止，精确控制掺杂剂浓度和该工艺的可扩展性仍然是一个挑战。在此，报道了一项通过金属有机化学气相沉积对完全凝聚的二维WSe薄膜进行可扩展原位Re原子掺杂的系统研究。掺杂剂浓度在衬底表面均匀分布，通过调节前驱体分压可实现低至<0.001% Re的精确控制浓度。此外，通过详细的实验和理论研究阐明了掺杂对WSe的形态、化学、光学和电子性质的影响，证实了Re在W位点的替代掺杂导致WSe的n型行为。所制备的背栅场效应晶体管的传输特性与掺杂剂浓度直接相关，当掺杂浓度超过1% Re时，器件性能会下降。该研究展示了一种可行的方法，能够高精度地引入真正的掺杂剂级杂质，并且可以扩大规模用于批量生产，以应用于数字电子之外的领域。
