Photoluminescence from Chemically Exfoliated MoS2
Photoluminescence from Chemically Exfoliated MoS2
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DOI：
10.1021/nl201874w
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发表时间：
2011-12-01
期刊：
影响因子：
10.8
通讯作者：
Chhowalla, Manish
中科院分区：
文献类型：
--
作者：
Eda, Goki;Yamaguchi, Hisato;Chhowalla, Manish
二硫化钼（MoS₂）单层二维晶体是一种光致发光的直接带隙半导体，这与它的体相材料形成鲜明对比。通过锂嵌入对体相MoS₂进行剥离是大规模合成单层晶体的一种有吸引力的途径。然而，由于锂嵌入过程中发生的结构变化，这种方法会导致MoS₂原有的半导体特性丧失。在此，我们报道化学剥离的MoS₂的结构和电子特性。研究发现，由锂嵌入产生的亚稳态金属相主导了刚剥离材料的特性，但温和退火会导致半导体相逐渐恢复。在退火温度高于300℃时，化学剥离的MoS₂表现出显著的带隙光致发光，与机械剥离的单层类似，这表明它们的半导体特性在很大程度上得到了恢复。
A two-dimensional crystal of molybdenum disulfide (MoS2) monolayer is a photoluminescent direct gap semiconductor in striking contrast to its bulk counterpart. Exfoliation of bulk MoS2 via Li intercalation is an attractive route to large-scale synthesis of monolayer crystals. However, this method results in loss of pristine semiconducting properties of MoS2 due to structural changes that occur during Li intercalation. Here, we report structural and electronic properties of chemically exfoliated MoS2. The metastable metallic phase that emerges from Li intercalation was found to dominate the properties of as-exfoliated material, but mild annealing leads to gradual restoration of the semiconducting phase. Above an annealing temperature of 300 degrees C, chemically exfoliated MoS2 exhibit prominent band gap photoluminescence, similar to mechanically exfoliated monolayers, indicating that their semiconducting properties are largely restored.