Details

Autor(en) / Beteiligte

• Na, Jeonghyeon
• Park, Changyeon
• Lee, Chang Hoi
• Choi, Won Ryeol
• Choi, Sooho
• Lee, Jae-Ung
• Yang, Woochul
• Cheong, Hyeonsik
• Campbell, Eleanor E. B
• Jhang, Sung Ho

Titel

Indirect Band Gap in Scrolled MoS[sub.2] Monolayers

Ist Teil von

• Nanomaterials (Basel, Switzerland), 2022-09, Vol.12 (19)

Ort / Verlag

MDPI AG

Erscheinungsjahr

2022

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• MoS[sub.2] nanoscrolls that have inner core radii of ∼250 nm are generated from MoS[sub.2] monolayers, and the optical and transport band gaps of the nanoscrolls are investigated. Photoluminescence spectroscopy reveals that a MoS[sub.2] monolayer, originally a direct gap semiconductor (∼1.85 eV (optical)), changes into an indirect gap semiconductor (∼1.6 eV) upon scrolling. The size of the indirect gap for the MoS[sub.2] nanoscroll is larger than that of a MoS[sub.2] bilayer (∼1.54 eV), implying a weaker interlayer interaction between concentric layers of the MoS[sub.2] nanoscroll compared to Bernal-stacked MoS[sub.2] few-layers. Transport measurements on MoS[sub.2] nanoscrolls incorporated into ambipolar ionic-liquid-gated transistors yielded a band gap of ∼1.9 eV. The difference between the transport and optical gaps indicates an exciton binding energy of 0.3 eV for the MoS[sub.2] nanoscrolls. The rolling up of 2D atomic layers into nanoscrolls introduces a new type of quasi-1D nanostructure and provides another way to modify the band gap of 2D materials.