Enhancement in charge transfer by non-ligand exchange process for colloidal hybrid organic(MEH-PPV):inorganic(CdSe) nanocomposites

In this work, we demonstrate the effect of surface modification of as-synthesized oleylamine-capped spherical CdSe QDs of size (5-7 nm). The as-prepared CdSe QDs are highly luminescent, monodispersive and exhibit energy transfer effects upon their dispersion in MEH-PPV polymer matrix. However, repetitive washing of CdSe QDs upon suitable chemical treatment leads to enhancement in charge transfer process as observed in their corresponding MEH-PPV: CdSe nanocomposites. Here, no evidence of agglomeration effects and surface states were found. This enhancement in charge transfer is mainly due to the partial removal of oleylamine capping ligand, which acts as a hindrance in the interaction between polymer and CdSe QDs. The importance of this study is that as-synthesized CdSe QDs show effective energy transfer whereas after chemical treatment, it shows enhanced charge transfer mechanism which makes their corresponding nanocomposites useful for different applications in organic electronic devices such as efficient electroluminescent (OLED) and photovoltaic (OPV) devices respectively.