Mandal Arnab, Ghosh Anima, Senanayak Satyaprasad P, Friend Richard H, Bhattacharyya Sayan
Department of Chemical Sciences and Centre for Advanced Functional Materials, Indian Institute of Science Education and Research (IISER), Kolkata, Mohanpur 741246, India.
School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni 752050, India.
J Phys Chem Lett. 2021 Feb 11;12(5):1560-1566. doi: 10.1021/acs.jpclett.0c03815. Epub 2021 Feb 3.
Since the invention of field effect transistors (FETs) in the mid-20th century, nanosheet (NS) transistors have been considered the future toward fulfilling Moore's law of scaling. Moving beyond conventional semiconductors, thickness tunable orthorhombic CsPbBr NSs are achieved by a perfect control in which the lateral dimension can be extended close to 1 μm. While 18-carbon-chain ligands produce ∼4.5 nm thick NSs, the strongly adsorbed less dynamic 8-carbon-chain ligands result in ∼9.2 nm NSs. Equipped with a minimum trap state density, a lower effective mass of charge carriers, and better carrier transport, the NSs enable an order of magnitude increase in the field effect mobility as compared to that of CsPbBr nanocubes, thus revealing the efficacy of designing the two-dimensional morphology. The -type field effect mobility (μ) of the photoexcited NSs reaches 10 cm V s at 200 K upon mitigation of the challenges of ionic screening and constrained tunneling probability across organic ligands.
自20世纪中叶场效应晶体管（FET）发明以来，纳米片（NS）晶体管一直被视为实现摩尔定律缩放的未来方向。超越传统半导体，通过完美控制实现了厚度可调的正交晶系CsPbBr纳米片，其横向尺寸可扩展至接近1μm。18碳链配体产生约4.5nm厚的纳米片，而强吸附的动态性较低的8碳链配体则产生约9.2nm厚的纳米片。纳米片具有最低的陷阱态密度、较低的电荷载流子有效质量和更好的载流子传输性能，与CsPbBr纳米立方体相比，其场效应迁移率提高了一个数量级，从而揭示了二维形态设计的有效性。在缓解了离子屏蔽和跨有机配体的受限隧穿概率等挑战后，光激发纳米片的n型场效应迁移率（μ）在200K时达到10 cm² V⁻¹ s⁻¹ 。
