Photocurrent of CdSe nanocrystals on single-walled carbon nanotube-field effect transistor

CdSe nanocrystals (NCs) have been decorated on single-walled carbon nanotubes (SWCNTs) by combining a method of chemically modified substrate along with gate-bias control. CdSe/ZnS core/shell quantum dots were negatively charged by adding mercaptoacetic acid. The silicon oxide substrate was decorated by octadecyltrichlorosilane and converted to hydrophobic surface. The negatively charged CdSe NCs were adsorbed on the SWCNT surface by applying a negative gate bias. The measured photocurrent clearly demonstrates that CdSe NCs decorated SWCNT can be used for photodetector and solar cell that are operable over a wide range of wavelengths.