2020年第67回応用物理学会春季学術講演会

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一般セッション(口頭講演)

17 ナノカーボン » 17.3 層状物質

[15a-A404-1~11] 17.3 層状物質

2020年3月15日(日) 09:00 〜 11:45 A404 (6-404)

上野 啓司(埼玉大)

10:15 〜 10:30

[15a-A404-6] PVD growth of AA stacking SnS through screw dislocation induced by substrate edge steps

〇(D)YihRen Chang1、Hayami Kawamoto1、Naoki Higashitarumizu1、Tomonori Nishimura1、Kosuke Nagashio1 (1.UTokyo)

キーワード:growth

Although Tin sulfide (SnS) has been highly demanded as power generator due to its high piezoelectric coefficient comparable to PZT, its piezoelectricity is limited to the odd number layers with non-centrosymmetric structure, that is, not bulk property. So far, we have demonstrated the ferroelectricity of monolayer SnS grown on mica substrate, which guarantees its piezoelectricity as well [1]. To further improve the power generation capacity, the bulk SnS with non-centrosymmetry (AA stacking) is highly required. The key idea is screw-dislocation-assisted spiral growth, which has already been observed to result in AA stacking in MoS2. However, in general, the growth mode on atomically flat mica substrate is the layer-by-layer growth with 2D nucleation. Here, HOPG substrate containing high density of atomic edge steps, unlike mica, is applied and these steps could work as origins for the spiral growth. In this study, screw-dislocation-assisted spiral growth is successfully demonstrated in PVD SnS. The growth mode of SnS and its crystallinity of SnS on mica as well as HOPG are analyzed and compared in detail through Raman spectrum as well as AFM images to gain the insight to obtain the piezoelectric bulk SnS.
Ref.: [1] N. Higashitarumizu, et al., JSAP Fall meeting, 19a-E308-5 (2019).