Injection of molecules onto hydrogen-terminated Si(100) surfaces via a pulse valve

Using scanning tunneling microscopy and spectroscopy, we tested a pulse-injection method for placing molecules onto hydrogen-terminated Si(100) surfaces. The target molecules were multiwalled carbon-nanotube and π-conjugated poly(3-hexylthiophene) molecules dispersed or dissolved into a hexane or chloroform solvent. The results suggest that pulse injection can be used for fixing a variety of molecules in organic solvents onto H-terminated Si(100) surfaces while keeping most of the surface intact.