Nanoimprinted substrates for high-yield production of topological insulator nanoribbons

作者：Wi Sungjin; Elezi Eljon; Liu Amy C; Ray Vishva; Sun Kai; Liang Xiaogan^*

来源：Applied Physics A-Materials Science & Processing, 2013, 111(3): 755-766.

DOI：10.1007/s00339-013-7694-3

We present a growth process mediated by nanoimprinted nanostructures specifically for producing bismuth selenide (Bi2Se3) topological insulator nanoribbons with a high yield. In this process, topological insulator nanostructures are grown on nanoimprinted gratings by using a nanoparticle-catalyzed vapor-liquid-solid mechanism. In comparison with the growth processes performed on flat and randomly rough substrates, such a nanograting-mediated growth method produces topological insulator nanoribbons with a higher yield (similar to 15 000 nanoribbons/mm(2)), a narrower average ribbon width (w (avg)< 60 nm), and a higher uniformity in ribbon width (sigma < 30 nm); effectively suppresses the formation of other unwanted morphologies; and also results in the axial growth of nanoribbons along specific in-plane directions relative to pre-structured gratings. Such technical merits of nanograting-mediated growth are attributed to the preferential nucleation of Bi2Se3 crystal seeds and the concomitant pinning of catalytic nanoparticles at ordered grating edges. Finally, Aharonov-Bohm interference oscillations in the magnetoresistance were observed and demonstrated the coherent transport of electrons through topological surface states of Bi2Se3 nanoribbons. This growth process in combination with large-area nanoimprint lithography could serve as an important foundation for nanomanufacturing topological insulator nanoribbons with controllable feature size, large-area uniformity, and ordering, suitable for applications in future low-dissipation nanoelectronics.

• 出版日期2013-6