摘要
Owing to the atomically thin nature,two-dimensional(2D)oxide materials have been widely reported to exhibit exciting transport and dielectric properties,such as fine gate controllability and ultrahigh carrier mobility,that outperform their bulk counterpart.However,unlike the successful synthesis of bulk oxide single crystals,reliable methods for synthesizing large-area single crystal of 2D oxide,that would suppress the negative influence from defective grain boundaries,remain unavailable,especially for nonlayered oxide.Herein,we report that the lattice symmetry between the substrate and cerium dioxide(CeO_(2))would allow for the aligned nucleation and epitaxial growth of CeO_(2)on sapphire substrates,enabling the wafer-sized growth of CeO_(2)single crystal.The careful tuning of the growth temperature and oxygen flow rate contributed to the harvesting of CeO_(2)wafer with reduced thickness and enhanced growth rates.The removal of grain boundaries improved the dielectric performance in terms of high dielectric strength(E_(bd)≈8.8 MV·cm^(-1)),suppressed leakage current,along with high dielectric constants(ε_(r)≈24).Our work demonstrates that with fine dielectric performance and ease of synthesizing wafer-sized single crystals,CeO_(2)can function as potential candidate as gate insulator for 2D-materials based nanoelectronics,and we believe the reported protocol of aligned nucleation can be extended to other 2D oxides.
基金
supported by the National Key Research and Development Program of China(No.2022YFA1204900)
the National Natural Science Foundation of China(Nos.52372038,12374035 and T2188101)
the Innovation Program for Quantum Science and Technology(No.2021ZD0302600).
作者简介
Zhuofeng Shi,contributed equally to this work;Muhammad Imran,contributed equally to this work;Xiaohui Chen,contributed equally to this work;Xin Liu,contributed equally to this work;correspondence author:Li Lin,linli-cnc@pku.edu.cn。
