Enhanced photovoltaic performance of bulk heterojunction based on ZnS quantum dots-grafted graphene. (December 2016)

• Record Type: Journal Article
• Authors: Jindal, Shikha; Giripunje, Sushama M.
• Is Part Of: Superlattices and microstructures. Volume 100(2016)
• Page Start: 683
• Page End: 693
• Publication Date: 2016-12
• Subjects: Semiconductors -- Nanocrystalline materials -- Quantum dots -- Zinc sulphide (ZnS) -- Graphene; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2016.10.030
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: ZnS quantum dots (QDs) and ZnS:graphene QDs were synthesized successfully via simple sonochemical method. X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) analysis revealed the average size of ZnS and ZnS:graphene QDs of the order of 3.7 nm and 8.4 nm, respectively. The band gap of ZnS:graphene QDs was tuned to 4.9 eV. Fourier transform infrared (FTIR) analysis confirms the formation of single phase ZnS QDs. The significant increase in conductivity of the order of 10 4 S/cm was observed in ZnS:graphene QDs. The bulk heterojunction devices ITO/PEDOT:PSS/P3HT:ZnSQDs/Al and ITO/PEDOT:PSS/P3HT:(ZnS:graphene)QDs/Al were fabricated. Here we demonstrate the increase in current density (from 2.44 μA/cm 2 to 98.4 μA/cm 2 ), alongwith the lower turn on voltage (decrease from 0.40 V to 0.12 V) by using the ZnS:graphene QDs as compared to pristine ZnS QDs in the active layer. Furthermore, this enhancement in current density shows that the ZnS:graphene QDs have a great potential for active layer in photovoltaic devices. Highlights: ZnS and ZnS:graphene quantum dots (QDs) were synthesized by sonochemical synthesis. Band gap of quantum dots has tuned from 6 eV to 4.9 eV. Current density of bulk heterojunction increases by incorporation of graphene. XRD and HRTEM confirms the formation of quantum dots.