1Chongqing Key Laboratory of Multi-scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chongqing 400714 2Key Laboratory of Weak-Light Nonlinear Photonics (Ministry of Education), School of Physics, Nankai University, Tianjin 300071 3University of Electronic Science and Technology of China, Chengdu 611731
Abstract：We provide a way to precisely control the geometry of a SiN$_x$ nanopore by adjusting the applied electric pulse. The pore is generated by applying the current pulse across a SiN$_x$ membrane, which is immersed in potassium chloride solution. We can generate single conical and cylindrical pores with different electric pulses. A theoretical model based on the Poisson and Nernst–Planck equations is employed to simulate the ion transport properties in the channel. In turn, we can analyze pore geometries by fitting the experimental current-voltage ($I$–$V$) curves. For the conical pores with a pore size of 0.5–2 nm in diameter, the slope angles are around $-2.5^{\circ}$ to $-10^{\circ}$. Moreover, the pore orifice can be enlarged slightly by additional repeating pulses. The conic pore lumen becomes close to a cylindrical channel, resulting in a symmetry $I$–$V$ transport under positive and negative biases. A qualitative understanding of these effects will help us to prepare useful solid-nanopores as demanded.
2016, Vol. 33 
