Solution-processable 2D semiconductors for high-performance large-area electronics
Solution-processable 2D semiconductors for high-performance large-area electronics
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DOI：
10.1038/s41586-018-0574-4
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发表时间：
2018-10-11
期刊：
影响因子：
64.8
通讯作者：
Duan, Xiangfeng
中科院分区：
文献类型：
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作者：
Lin, Zhaoyang;Liu, Yuan;Duan, Xiangfeng
二维（2D）材料由通过货车德瓦尔斯力结合的原子级薄晶体层组成，由于其在包括电子学、光电子学和催化剂在内的各种技术中的潜力而引起了人们的极大兴趣（1-10）。特别是，可溶液加工的2D半导体（如MoS 2）纳米片是大面积薄膜电子器件的有吸引力的构建块。与传统的零维和一维纳米结构（分别为量子点和纳米线）相比，它们通常受到表面悬挂键和相关捕获态的困扰，2D纳米片具有无悬挂键的表面。通过堆叠多个纳米片产生的薄膜具有原子级清洁的货车范德华界面，因此保证了优异的电荷传输（11-15）。然而，制备高质量的可溶液加工的2D半导体纳米片仍然是一个挑战。例如，使用锂嵌入和剥离产生的MoS 2纳米片和薄膜受到金属1 T相的存在和差的电性能的困扰（迁移率约为0.3平方厘米/伏/秒，开/关比小于10）（2，12），并且通过液体剥离产生的材料表现出固有的宽厚度分布，这导致差的膜质量和不令人满意的薄膜电性能（迁移率约为0.4平方厘米/伏/秒，开/关比约为100）（14，16，17）。在这里，我们报告了一个一般的方法来制备高度均匀的，溶液加工，相纯的半导体纳米片，其中包括电化学嵌入的季铵分子（如四庚基溴化铵）到2D晶体，然后通过温和的超声处理和剥离过程。通过精确控制插层化学，我们获得了具有窄厚度分布的相纯的半导体2 H-MoS 2纳米片。然后，这些纳米片被进一步加工成高性能薄膜晶体管，其室温迁移率约为10平方厘米/伏/秒，开/关比为10（6），大大超过了以前的溶液处理的MoS 2薄膜晶体管。大面积薄膜晶体管阵列的可扩展制造使得能够构建功能逻辑门和计算电路，包括反相器，NAND，NOR，AND和XOR门以及逻辑半加法器。我们还将我们的方法应用于其他2D材料，包括WSe 2，Bi 2Se 3，NbSe 2，In 2Se 3，Sb 2 Te 3和黑磷，展示了其生成多功能溶液加工2D材料的潜力。
Two-dimensional (2D) materials, consisting of atomically thin crystal layers bound by the van der Waals force, have attracted much interest because of their potential in diverse technologies, including electronics, optoelectronics and catalysis(1-10). In particular, solution-processable 2D semiconductor (such as MoS2) nanosheets are attractive building blocks for large-area thin-film electronics. In contrast to conventional zero-and one-dimensional nanostructures (quantum dots and nanowires, respectively), which are typically plagued by surface dangling bonds and associated trapping states, 2D nanosheets have dangling-bond-free surfaces. Thin films created by stacking multiple nanosheets have atomically clean van der Waals interfaces and thus promise excellent charge transport(11-15). However, preparing high-quality solution-processable 2D semiconductor nanosheets remains a challenge. For example, MoS2 nanosheets and thin films produced using lithium intercalation and exfoliation are plagued by the presence of the metallic 1T phase and poor electrical performance (mobilities of about 0.3 square centimetres per volt per second and on/off ratios of less than 10)(2,12), and materials produced by liquid exfoliation exhibit an intrinsically broad thickness distribution, which leads to poor film quality and unsatisfactory thin-film electrical performance (mobilities of about 0.4 square centimetres per volt per second and on/off ratios of about 100)(14,16,17). Here we report a general approach to preparing highly uniform, solution-processable, phase-pure semiconducting nanosheets, which involves the electrochemical intercalation of quaternary ammonium molecules (such as tetraheptylammonium bromide) into 2D crystals, followed by a mild sonication and exfoliation process. By precisely controlling the intercalation chemistry, we obtained phase-pure, semiconducting 2H-MoS2 nanosheets with a narrow thickness distribution. These nanosheets were then further processed into high-performance thin-film transistors, with room-temperature mobilities of about 10 square centimetres per volt per second and on/off ratios of 10(6) that greatly exceed those obtained for previous solution-processed MoS2 thin-film transistors. The scalable fabrication of large-area arrays of thin-film transistors enabled the construction of functional logic gates and computational circuits, including an inverter, NAND, NOR, AND and XOR gates, and a logic half-adder. We also applied our approach to other 2D materials, including WSe2, Bi2Se3, NbSe2, In2Se3, Sb2Te3 and black phosphorus, demonstrating its potential for generating versatile solution-processable 2D materials.