Largely Enhanced Mobility in Trilayered LaAlO3/SrTiO3/LaAlO3 Heterostructures

作者：Hu Hai Long; Anh Pham; Tilley Richard; Zeng Rong; Tan Thiam Teck; Kong Chun Hua; Webster Richard; Wang Danyang^*; Li Sean^*

来源：ACS Applied Materials & Interfaces, 2018, 10(24): 20950-20958.

DOI：10.1021/acsami.7b11218

• laser molecular beam epitaxy
• LaAlO3/SrTiO3/LaAlO3 heterostructures
• dielectric permittivity
• carrier effective mass
• two-dimensional electron gas
• electron mobility

LaAlO3 (LAO)/SrTiO3 (STO)/LaAlO3 (LAO) heterostructures were epitaxially deposited on TiO2-terminated (100) SrTiO3 single-crystal substrates by laser molecular beam epitaxy. The electron Hall mobility of 1.2 x 10(4) cm(2)/Vs at 2 K was obtained in our trilayered heterostructures grown under 1 x 10(-5) Torr, which was significantly higher than that in single-layer 5 unit cells LAO (similar to 4 X 10(3) cm(2)/V s) epitaxially grown on (100) STO substrates under the same conditions. It is believed that the enhancement of dielectric permittivity in the polar insulating trilayer can screen the electric field, thus reducing the carrier effective mass of the two-dimensional electron gas formed at the TiO2 interfacial layer in the substrate, resulting in a largely enhanced mobility, as suggested by the first-principle calculation. Our results will pave the way for designing high-mobility oxide nanoelectronic devices based on LAO/STO heterostructures.

• 出版日期2018-6-20