Normal and Resonant Raman Spectra of CuPc-MWCNT Blend

Abstract

Understanding molecular electronics is critical in advance of organic devices. Intermolecular interaction between copper phthalocyanine (CuPc) and multi-walled carbon nanotubes (MWCNT) was studied using infrared spectroscopy and confocal Raman microscope. The organics were prepared using solution processing method at ambient atmosphere. The infrared spectrum showed the signal from the lower wavenumber was largely dominated by broad absorption and the lacking of ‘fingerprints’ peaks provided no information on the MWCNT. Raman absorption spectra under normal (λ = 532 nm) and resonant (λ = 633 nm) were obtained to tackle the disadvantages in the former method. Fingerprint peaks of CuPc in frequency of 600 - 1600 cm-1 emerged under both excitation wavelengths. New 480 cm-1, 1100 cm-1 and 1300 cm-1 peaks were found in resonant spectra. There were no strong evidence of presence and interaction between CuPc and MWCNT detected in these measurements possibly due to overlapping vibrational states between the two compounds and insufficient quantity of MWCNT in the sample.