Electro-optical properties improvement of organic composite using p-nitro-benzylidenemalonotrile-based small organic molecules

The solution-processable small organic molecules have turned into one of the most promising semiconductors due to their exclusive properties in the inexpensive optoelectronic field. In this work, we report the study of the incorporation effect of the small organic molecules of p-nitro-benzylidenemalonotrile (N(O₂)-BMN) into conjugated polymer poly(3-hexylthiophene) (P3HT) on the optical and electrical properties. The UV–visible and photoluminescence (PL) responses were performed to confirm the enhancement of the optical properties. PL results showed that P3HT: N(O₂)-BMN composite with (1:1.25) ratio has the best charge transfer efficiency that occurs between both compounds. The current–voltage characteristics through dark J (V) revealed that the ITO/P3HT: N(O₂) BMN/Al structure had a diode behaviour with a relatively low threshold voltage ((V_{{{ ext{th}}}})). We have estimated the different electrical parameters such as the saturation current, barrier high (({Phi }_{{ ext{b}}} )) and the ideality factor (n). Moreover, we have evaluated the different charge transport mechanisms by the analyses of J–V characteristics in a double logarithmic scale under dark conditions. The obtained results proved that the incorporation of N(O₂)-BMN enhances the electrical properties of the composite.