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In the field of catalysis and energy applications, heterostructures of halide perovskite nanocrystals (NCs) and functionalized graphene are emerging as promising materials. In such heterostructures, it is critical to gain insights into the knowledge that governs the charge and energy transfer dynamics between the components of the heterostructures because it directly affects the efficiency of devices. In this work, we present heterostructures that consist of mercaptoacetic acid (MAA)-functionalized CsPbBr 3 NCs and alanine-functionalized graphene. The surface functionalization of CsPbBr 3 NCs and graphene enables an effective attachment of the NCs and graphene. The use of MAA as a functionalizing ligand not only passivates the surface of NCs but also provides the possibility of tuning the size of NCs and further coupling with alanine-functionalized graphene. Varying the amount of MAA allows us to synthesize the brightest CsPbBr 3 NCs with an absolute photoluminescence quantum yield (PLQY) of 49% and an emission spectral width of 25 nm. By combining alanine-functionalized graphene, the photoluminescence (PL) quenching of the NCs is observed. The photoexcited electron transfer from NCs to alanine-functionalized graphene is responsible for the occurrence of PL quenching that is advocated by time-resolved photoluminescence (TRPL) studies and cyclic voltammetry (CV) analysis. Our work provides a method to control the energetics and analyze the types of charge transfer in functionalized perovskite NCs and graphene heterostructures and motivates further research about the basic knowledge of charge transfer in functionalized donor−acceptor heterostructures.

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Silver (Ag) doped ZnO (SZO) nanomaterials were synthesized by hydrothermal method and characterized. ZnO nanostructures were doped with 0.0%, 0.5%, 1%, 1.5mol% Ag. These obtained SZO nanomaterials were analyzed using X-ray diffraction measurement (XRD), Scanning Electron Microscopy (SEM), and Energy Dissipative X-ray (EDX) spectroscopy. The structural analysis confirmed the formation of synthesized SZO samples having a hexagonal ZnO wurtzite phase. The morphology of SZO samples changed partially and the ZnO nanorod length increased somewhat as the Ag doping ratio increased. Despite this increase, it was seen that the average crystal sizes first increased and then decreased. The crystallite sizes calculated from XRD data for 0.0, 0.5, 1.0 and 1.5mol% SZO were obtained as 41, 42, 38 and 37 nm, respectively. Ag doping concentration has increased the absorbance of SZO nanomaterials increased and the transmission decreased was observed. The band gap of the 0.0%, 0.5%, 1.0% and 1.5mol% SZO nanomaterials were measured 3.19, 3.18, 3.16 and 3.19 eV, respectively. Then dye sensitized solar cells (DSSCs) were fabricated using these SZO nanomaterials, cis-Bis(isothiocyanato)(2,2′bipyridyl-4,4′-dicarboxylato) (4,4′-di-nonyl-2′-bipyridyl) ruthenium (II) dye (Z907), (Ditetrabutylammonium cis-bis(isothiocyanato) bis (2,20-bipyridyl-4,40 dicarboxylato) ruthenium (II) dye (N719) and examined their photovoltaic performances. The calculated efficiencies of DSSCs fabricated using Z907 dye for 0.0%, 0.5%, 1.0% and 1.5mol% SZO were 0.005, 0.51, 0.46 and 0.22%, respectively. Then the calculated efficiencies of DSSCs fabricated using N719 dye for 0.0%, 0.5%, 1.0% and 1.5mol% SZO were 0.06, 0.17, 0.07 and 0.06%, respectively. In both works, DSSCs with ZnO film doped with 0.5mol% SZO showed the best photovoltaic performance. Consequently, these results indicated that the synthesized SZO nanomaterial for DSSCs of the optimum ratio of Ag doping is 0.5mol% clearly.