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Extremely Light Carrier‐Effective Mass in a Distorted Simple Metal Oxide
Author(s) -
Kim Gowoon,
Zhang YuQiao,
Min Taewon,
Suh Hoyoung,
Jang Jae Hyuck,
Kong Hyeonjun,
Lee Joonhyuk,
Lee Jaekwang,
Jeon TaeYeol,
Lee Inwon,
Cho Jinhyung,
Ohta Hiromichi,
Jeen Hyoungjeen
Publication year - 2019
Publication title -
advanced electronic materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.25
H-Index - 56
ISSN - 2199-160X
DOI - 10.1002/aelm.201800504
Subject(s) - materials science , effective mass (spring–mass system) , oxide , metal , electron mobility , anisotropy , electrical resistivity and conductivity , epitaxy , crystal (programming language) , electron , condensed matter physics , optoelectronics , nanotechnology , optics , electrical engineering , metallurgy , physics , layer (electronics) , quantum mechanics , computer science , programming language , engineering
Exotic electron transport properties such as quasi 1D conductivity are useful to realize advanced electronic devices showing unique properties. Anisotropic electron transport properties are often found in complex metal oxides due to their complicated crystal structures. Although simple metal oxides with distorted crystal structures could also be expected to show anisotropic electron transport properties, it is rarely studied most likely due to the lack of their high‐quality epitaxial films. Here anisotropic electron transport properties, showing “fast electron transport path,” in a simple distorted metal oxide, NbO 2 , is reported. High‐quality NbO 2 epitaxial films with different crystallographic orientations on (0001) and (1 1 ¯ 02) α‐Al 2 O 3 single crystal substrates are fabricated, and the electron transport properties at room temperature are measured. Both the resistivity and absolute value of the thermopower along the [11 2 ¯ ] NbO 2 is pretty small as compared with other directions. Experimentally obtained electron carrier effective mass in the [11 2 ¯ ] direction is surprisingly small, only 0.051 m e , which is similar to that of high‐mobility GaAs. Since simple metal oxides have several advantages against complex oxides in view of easy fabrication, the present results will be beneficial for realizing advanced electronic devices using simple metal oxides.