Hao Qiaoyan, Liu Jidong, Wang Gang, Chen Jiewei, Gan Haibo, Zhu Jiaqi, Ke Yuxuan, Chai Yang, Lin Junhao, Zhang Wenjing
International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China.
Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China.
ACS Nano. 2020 Sep 22;14(9):11373-11382. doi: 10.1021/acsnano.0c03556. Epub 2020 Aug 27.
Indium selenide (InSe) has become a research hotspot because of its favorable carrier mobility and thickness-tunable band gap, showing great application potential in high-performance optoelectronic devices. The trend of miniaturization in optoelectronics has forced the feature sizes of the electronic components to shrink accordingly. Therefore, atomically thin InSe crystals may play an important role in future optoelectronics. Given the instability and ultralow photoluminescent (PL) emission of mechanically exfoliated ultrathin InSe, synthesis of highly stable mono- and few-layer InSe nanosheets with high PL efficiency has become crucial. Herein, ultrathin InSe nanosheets were prepared thermal annealing of electrochemically intercalated products from bulk InSe. The size and yield of the as-prepared nanosheets were up to ∼160 μm and ∼70%, respectively, and ∼80% of the nanosheets were less than five layer. Impressively, the as-prepared nanosheets showed greatly enhanced stability and PL emission because of surface modification by carbon species. Efficient photoresponsivity of 2 A/W was achieved in the as-prepared nanosheet-based devices. These nanosheets were further assembled into large-area thin films with photoresponsivity of 16 A/W and an average Hall mobility of about 5 cm V s. Finally, one-dimensional (1D) InSe nanoscrolls with a length up to 90 μm were constructed by solvent-assisted self-assembly of the exfoliated nanosheets.
硒化铟（InSe）因其良好的载流子迁移率和可厚度调谐的带隙而成为研究热点，在高性能光电器件中显示出巨大的应用潜力。光电子学的小型化趋势迫使电子元件的特征尺寸相应缩小。因此，原子级薄的InSe晶体可能在未来的光电子学中发挥重要作用。鉴于机械剥离的超薄InSe的不稳定性和超低光致发光（PL）发射，合成具有高PL效率的高度稳定的单层和少层InSe纳米片变得至关重要。在此，通过对块状InSe的电化学插层产物进行热退火制备了超薄InSe纳米片。所制备的纳米片的尺寸和产率分别高达约160μm和约70%，并且约80%的纳米片少于五层。令人印象深刻的是，由于碳物种的表面改性，所制备的纳米片显示出大大增强的稳定性和PL发射。在所制备的基于纳米片的器件中实现了2 A/W的高效光响应性。这些纳米片进一步组装成大面积薄膜，其光响应性为16 A/W，平均霍尔迁移率约为5 cm² V⁻¹ s⁻¹。最后，通过溶剂辅助的剥离纳米片自组装构建了长度高达90μm的一维（1D）InSe纳米卷。
