Microfluidic channel integrated solution state diode using semiconductor polymer nanorods with nanogap electrodes

A microfluidic channel integrated solution state diode, which uses regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT):dichlorobenzene solution as semiconductor between highly doped p-type silicon and aluminum electrodes, is built. Electrodes are separated by a 40 nm gap, which is obtained by the SiO₂ layer. Diode is formed at the Al/SiO₂/Si interface in contact with solution. A microfluidic channel is fabricated on top of the electrode structure to hold the solution. Multiple Al electrodes are formed and connected in parallel forming groups with different numbers of lines, to increase the total interface area of the diode. In I-V measurements, 16.8 nA forward current value is obtained for 8 V input voltage with single Al line, whereas this value is 421.4 nA with 25 parallel connected lines. Forward current of this novel diode increases linearly with the total interface area.