Solid State Physics Laboratory, Timarpur, Delhi, 110054, India. Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
Nanotechnology. 2019 Mar 8;30(10):105706. doi: 10.1088/1361-6528/aaf840. Epub 2018 Dec 12.
In this report, the precise alignment of catalyst free InAs nanowires (NWs) on pre-patterned Au microelectrodes by dielectrophoresis (DEP) technique for gas sensing applications is presented. The catalyst free InAs NWs have been grown on Si (111) substrate by molecular beam epitaxy (MBE) technique. The effect of dispersing solvents, electrode geometries and gaps, magnitude, frequency and duration of applied voltage etc, has been studied for aligning the InAs NWs by DEP technique. Current-voltage (I-V) measurements on the aligned NWs show linear behavior at room temperature (300 K), which changes to nonlinear at lower temperatures and higher voltages. The nonlinearity at lower temperatures and higher voltages is well explained by a space charge limited current contribution, which further gives a quantitative estimation of free charge carriers and trap density. The DEP aligned NWs exhibit good sensing response upon exposure to 10 ppm NO gas.
在本报告中，提出了通过介电泳（DEP）技术将无催化剂的 InAs 纳米线（NWs）精确对准预先图案化的 Au 微电极，用于气体传感应用。无催化剂的 InAs NWs 通过分子束外延（MBE）技术在 Si（111）衬底上生长。研究了分散溶剂、电极几何形状和间隙、施加电压的幅度、频率和持续时间等因素对通过 DEP 技术对齐 InAs NWs 的影响。在室温（300 K）下，对对齐的 NWs 进行电流-电压（I-V）测量显示出线性行为，而在较低温度和较高电压下则变为非线性。较低温度和较高电压下的非线性很好地解释了空间电荷限制电流的贡献，这进一步给出了自由载流子和陷阱密度的定量估计。DEP 对齐的 NWs 在暴露于 10 ppm 的 NO 气体时表现出良好的传感响应。
