Indirect-to-direct band gap crossover of single walled MoS2 nanotubes
Indirect-to-direct band gap crossover of single walled MoS2 nanotubes
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DOI：
10.35848/1347-4065/abffc6
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发表时间：
2020-11
影响因子：
1.5
通讯作者：
Kaoru Hisama;M. Maruyama;S. Chiashi;S. Maruyama;S. Okada
中科院分区：
文献类型：
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作者：
Kaoru Hisama;M. Maruyama;S. Chiashi;S. Maruyama;S. Okada
采用密度泛函理论研究了单壁二硫化钼纳米管（MoS 2 NTs）的电子结构.扶手椅型MoS 2纳米管是直径高达约5.2 nm的间接带隙半导体，而直径较大的纳米管是带边位于k = 2π/3附近的直接带隙半导体。这一发现意味着具有大直径的MoS 2 NT应表现出与2D单层MoS 2片相似的光致发光。这种间接到直接的带隙交叉解释了由于曲率引起的拉伸应变而导致的小直径NT中的Γ点处的价带峰的相对向上移位。
Using density functional theory, the electronic structures of single walled molybdenum disulfide nanotubes (MoS2 NTs) were investigated. The armchair MoS2 NTs are indirect gap semiconductors for diameters up to approximately 5.2 nm, while those with larger diameters are direct gap semiconductors with band edges located in the vicinity of k = 2π/3. This finding implies that MoS2 NTs with large diameters should exhibit similar photoluminescence to 2D monolayer MoS2 sheets. This indirect-to-direct band gap crossover accounts for the relative upward shift of the valence band peak at the Γ point in small diameter NTs, owing to the tensile strain arising from curvature.