Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei, 10607, Taiwan.
Nanotechnology. 2017 Sep 27;28(39):395201. doi: 10.1088/1361-6528/aa7d99. Epub 2017 Jul 4.
ZnS nanowires were synthesized via a vapor-liquid-solid mechanism and then fabricated into a single-nanowire field-effect transistor by focused ion beam (FIB) deposition. The field-effect electrical properties of the FIB-fabricated ZnS nanowire device, namely conductivity, mobility and hole concentration, were 9.13 Ω cm, 13.14 cm V sand 4.27 × 10 cm, respectively. The photoresponse properties of the ZnS nanowires were studied and the current responsivity, current gain, response time and recovery time were 4.97 × 10 A W, 2.43 × 10, 9 s and 24 s, respectively. Temperature-dependent I-V measurements were used to analyze the interfacial barrier height between ZnS and the FIB-deposited Pt electrode. The results show that the interfacial barrier height is as low as 40 meV. The energy-dispersive spectrometer elemental line scan shows the influence of Ga ions on the ZnS nanowire surface on the FIB-deposited Pt contact electrodes. The results of temperature-dependent I-V measurements and the elemental line scan indicate that Ga ions were doped into the ZnS nanowire, reducing the barrier height between the FIB-deposited Pt electrodes and the single ZnS nanowire. The small barrier height results in the FIB-fabricated ZnS nanowire device acting as a high-gain photosensor.
通过汽-液-固（VLS）机制合成了 ZnS 纳米线，然后通过聚焦离子束（FIB）沉积将其制成单根纳米线场效应晶体管。FIB 制造的 ZnS 纳米线器件的场效应电特性，即电导率、迁移率和空穴浓度，分别为 9.13 Ω cm、13.14 cm² V s 和 4.27×10¹⁷ cm⁻³。研究了 ZnS 纳米线的光响应特性，电流响应率、电流增益、响应时间和恢复时间分别为 4.97×10¹⁷ A W⁻¹、2.43×10⁴、9 s 和 24 s。通过温度相关的 I-V 测量来分析 ZnS 与 FIB 沉积的 Pt 电极之间的界面势垒高度。结果表明，界面势垒高度低至 40 meV。能谱仪元素线扫描显示 Ga 离子对 FIB 沉积的 Pt 接触电极上的 ZnS 纳米线表面的影响。温度相关的 I-V 测量和元素线扫描的结果表明，Ga 离子被掺杂到 ZnS 纳米线中，降低了 FIB 沉积的 Pt 电极与单个 ZnS 纳米线之间的势垒高度。小的势垒高度使得 FIB 制造的 ZnS 纳米线器件成为高增益光传感器。
