Electrochemical approach for fabricating nanogap electrodes with well controllable separation

An electrochemical technique for fabricating nanogaps is proposed, which utilizes an in situ gap-impedance-tuning mechanism to realize precise control of gap separation. Nanogap electrodes with gap separation from tens of nanometer to sub 10 nm have been fabricated by combining conventional photolithography and this controlled electrodeposition technique. The gap separation can be tuned by changing monitoring parameters based on a homemade electrochemical setup, which provides high sensitivity and reproducibility. In addition, a possible mechanism for controlling gap separation at tens of nanometer level at present conditions was discussed.