2019年第80回応用物理学会秋季学術講演会

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一般セッション(ポスター講演)

15 結晶工学 » 15.1 バルク結晶成長

[19a-PB4-1~2] 15.1 バルク結晶成長

2019年9月19日(木) 09:30 〜 11:30 PB4 (第二体育館)

09:30 〜 11:30

[19a-PB4-1] The low temperature liquid phase growth of layered semiconductor InSe and its optical properties

Chao Tang1、Yohei Sato1、Katsuya Watana1、Junya Osaki1、Tadao Tanabe1、Yutaka Oyama1 (1.Tohoku Univ.)

キーワード:Liquid phase growth, Van der Waals crystal, THz optical property

Two-dimensional (2D) materials, including InSe and GaSe have attracted more and more attentions nowadays. The high quality InSe crystals have been successfully grown by the temperature difference method under controlled vapor pressure (TDM-CVP), in which the crystals can be prepared at the temperature far lower than their melting point (Fig. 1). It is confirmed by characterizations such as Raman spectroscopy and X-ray diffraction that the as-grown crystals have favorable crystallinity, which may attribute to the low-temperature and static growth process. On the other hand, it is known that the GaSe is a typical nonlinear optic crystal used for frequency conversion. We analyzed the nonlinear optical coefficient theoretically by density function theory and confirmed the result in infrared range by second harmonic generation (SHG) experiments. The calculation matches to experiment exactly and also indicate that the InSe, with similar lattice structure with GaSe, also has potential of nonlinear optical application. Indeed, in our previous transmittance measurement on InSe using different frequency generation (DFG) terahertz (THz) light source, it was shown that the absorption in terahertz range of InSe was far smaller than that of GaSe (Fig. 2). The present study has clarified the potential of InSe to be applied as nonlinear optical crystal for THz generation.