Self-assembled monolayers (SAMs) of thiol-derivatized porphyrin molecules on Au substrate have attracted extensive interest for use in sensing, molecular recognition, and molecular electronics. Here, we synthesized tetra[p-(3-mercaptopropyloxy)phenyl]porphyrin (PPS4) with four "clips" for SAMs. The results demonstrated that PPS4 could form excellent SAMs on gold surface wherein the molecules oriented on substrates with a tilted angle. Self-assembled nanojunctions of PPS4 were fabricated by using gold nanogap electrodes (gap width: ca. 100 nm), which exhibited nonlinear current-voltage characteristics, indicating tunneling injection of current from Au electrodes into PPS4. With the light on/off, the nanojunctions switched between low/high impedance states as nanometer scaled photoswitchers.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films