Sulfur-Doped Black Phosphorus Field-Effect Transistors with Enhanced Stability
Sulfur-Doped Black Phosphorus Field-Effect Transistors with Enhanced Stability
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具有增强稳定性的掺硫黑磷场效应晶体管
DOI：
10.1021/acsami.7b19169
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发表时间：
2018-03-21
影响因子：
9.5
通讯作者：
Liu, Zhongyuan
中科院分区：
文献类型：
--
作者：
Lv, Weiming;Yang, Bingchao;Liu, Zhongyuan
黑磷（BP）具有随厚度可调的带隙、高迁移率和大的I-on/I-off Toff ratio等特点，在未来的二维电子和光电子器件中具有广泛的应用前景。然而，它在环境条件下的不稳定性给研究带来了挑战，限制了它的实际应用。在这项工作中，我们提出了一种可行的方法来抑制硫(5)掺杂对BP的降解。制备的掺s BP少层场效应晶体管（fet）在环境条件下表现出更稳定的晶体管性能。在空气中暴露21天后，典型的掺s BP fet器件的载流子迁移率从607 cm(2) V-1 s（-1）下降到470 cm(2) V-1 s(-1)（仍然高达77.4%），并且仍然保持了类似于10(3)的大I-on/I-off比。原子力显微镜分析，包括表面形貌、厚度和粗糙度，也表明s掺杂BP的降解率比BP低。第一线原理计算表明，掺杂的S原子更倾向于在BP表面以悬空形式化学吸附，S掺杂BP的稳定性增强可归因于BP的导带最小值降移到O-2/O-2（-）的氧化还原电位以下。我们的工作表明，S掺杂是提高黑磷稳定性的有效途径。
Black phosphorus (BP) has drawn great attention owing to its tunable band gap depending on thickness, high mobility, and large I-on/I-off Toff ratio, which makes BP attractive for using in future two-dimensional electronic and optoelectronic devices. However, its instability under ambient conditions poses challenge to the research and limits its practical applications. In this work, we present a feasible approach to suppress the degradation of BP by sulfur (5) doping. The fabricated S-doped BP few layer field-effect transistors (FETs) show more stable transistor performance under ambient conditions. After exposing to air for 21 days, the charge-carrier mobility of a representative S-doped BP FETs device decreases from 607 to 470 cm(2) V-1 s(-1) (remained as high as 77.4%) under ambient conditions and a large I-on/I-off ratio of similar to 10(3) is still retained. The atomic force microscopy analysis, including surface morphology, thickness, and roughness, also indicates the lower degradation rate of S-doped BP compared to BP. First-principles calculations show that the dopant S atom energetically prefers to chemisorb on the BP surface in a dangling form and the enhanced stability of S-doped BP can be ascribed to the downshift of the conduction band minimum of BP below the redox potential of O-2/O-2(-). Our work suggests that S doping is an effective way to enhance the stability of black phosphorus.