Direct, mask- and solvent-free printing of molecular organic semiconductors

The organic vapor jet printing (OVJP) method used for direct and efficient deposition of organic semiconductors, was analyzed. A pentacene thin film transistor (TFT) was printed using OVJP. The high values of effective channel mobility was attributed to the use of octadecyl trichlorosilane (OTS), and the ordered nature of the deposited pentacene films. It was observed that by seeding heavy organic molecules in much lighter carrier gas, higher surface impact energy and effective temperature can be achieved in growth of crystalline thin films. The results show that OVJP method is convenient for combinatorial experiments on dependence of electronic device performance on film composition and crystallinity.