• Energy Research

AbstractEfficient FRET systems are developed combining colloidal CdSe quantum dots (QDs) donors and BODIPY acceptors. To promote effective energy transfer in FRET architectures, the distance between the organic fluorophore and the QDs needs to be optimized by a careful system engineering. In this context, BODIPY dyes bearing amino‐terminated functionalities are used in virtue of the high affinity of amine groups in coordinating the QD surface. A preliminary QD surface treatment with a short amine ligand is performed to favor the interaction with the organic fluorophores in solution. The successful coordination of the dye to the QD surface, accomplishing a short donor–acceptor distance, provides effective energy transfer already in solution, with efficiency of 76 %. The efficiency further increases in the solid state where the QDs and the dye are deposited as single coordinated units from solution, with a distance between the fluorophores down to 2.2 nm, demonstrating the effectiveness of the coupling strategy.

Phase-pure and highly crystalline AgBiI4 NCs are synthesized by hot-injection synthesis route. The iodine-rich surface of the NCs enable their impressive long-term environmental and thermal stabilities. This study shines light on the surface-electronic structure relationship for AgBiI4 NCs.

A low-cost approach for unconventional hole-transporting materials is reported. Their sustainable combination with the sole tert-butyl pyridine as an additive unprecedently stabilises the corresponding perovskite solar cells up to 400 days.

Novel co-sensitizers have been structurally tailored and implemented in multi-sensitized devices demonstrating synergic efficiency enhancement.

We here report the implementation of poly[(3-N-methylimidazoliumpropyl)methylsiloxane-co-dimethylsiloxane]iodides as suitable polymeric hosts for a novel class of in situ cross-linkable iodine/iodide-based gel-electrolytes for dye-sensitized solar cells. The polymers are first partially quaternized and then subjected to a thermal cross-linking which allows the formation of a 3D polymeric network which is accompanied by a dramatic enhancement of the ionic conductivity.

AbstractThis study deals with the synthesis and characterization of two π‐extended organic sensitizers (G1 and G2) for applications in dye‐sensitized solar cells. The materials are designed with a D–A–π–A structure constituted by i) a triarylamine group as the donor part, ii) a dithienyl‐benzothiadiazole chromophore followed by iii) a further ethynylene‐thiophene (G1) or ethynylene‐benzene (G2) π‐spacer and iv) a cyano‐acrylic moiety as acceptor and anchoring part. An unusual structural extension of the π‐bridge characterizes these structures. The so‐configured sensitizers exhibit a broad absorption profile, the origin of which is supported by density functional theory. The absence of hypsochromic shifts as a consequence of deprotonation as well as notable optical and electrochemical stabilities are also observed. Concerning the performances in devices, electrochemical impedance spectroscopy indicates that the structural modification of the π‐spacer mainly increases the electron lifetime of G2 with respect to G1. In devices, this feature translates into a superior power conversion efficiency of G2, reaching 8.1 %. These results are comparable to those recorded for N719 and are higher with respect to literature congeners, supporting further structural engineering of the π‐bridge extension in the search for better performing π‐extended organic sensitizers.