Photo-induced dynamic processes in perovskite solar cells: the influence of perovskite composition in the charge extraction and the carrier recombination.

We describe in this work how the use of the photo-induced charge extraction (PICE) technique can be useful to study and understand the relationship between perovskite composition, ion migration processes and solar cell performance. Our results show that varying the organic cation and halide composition in perovskite crystals has an effect on the charge extraction process, which is related to the differences in the ion migration process occurring during light irradiation. Moreover, we do also observe that different perovskites also show differences in interfacial carrier recombination kinetics under operando conditions but the dynamics are too fast to be influenced by the ion migration.

Pyrrolo[3,2-b]pyrrole as the Central Core of the Electron Donor for Solution-Processed Organic Solar Cells.

A series of three small-molecule acceptor-donor-acceptor (A-D-A) compounds with a tetraaryl-1,4-dihydropyrrolo[3,2-b]pyrrole as the central building block were synthesized and fully characterized. These molecules present high thermal stability and suitable HOMO-LUMO energy levels making them feasible electron-donor materials in bulk heterojunction organic solar cells (BHJ-OSC). Moreover, theoretical work predicts of a lack of planarity and no π-π stacking, furthermore.

Selective Organic Contacts for Methyl Ammonium Lead Iodide (MAPI) Perovskite Solar Cells: Influence of Layer Thickness on Carriers Extraction and Carriers Lifetime.

We have fabricated MAPI solar cells using as selective contacts PEDOT:PSS polymer for holes and PCBM-C70 fullerene derivative for electrons. The thickness of MAPI, PCBM-C70, and PEDOT:PSS layers has been varied in order to evaluate the contribution of each layer to the final device performance. We have measured the devices capacitance under illumination and the charge carrier's lifetime using photoinduced time-resolved techniques.

Fully Solution-Processed n-i-p-Like Perovskite Solar Cells with Planar Junction: How the Charge Extracting Layer Determines the Open-Circuit Voltage.

Fully solution-processed direct perovskite solar cells with a planar junction are realized by incorporating a cross-linked [6,6]-phenyl-C61-butyric styryl dendron ester layer as an electron extracting layer. Power conversion efficiencies close to 19% and an open-circuit voltage exceeding 1.1 V with negligible hysteresis are delivered.

Cyclopentadithiophene organic core in small molecule organic solar cells: morphological control of carrier recombination.

Two new planar and symmetrical A-D-A (electron acceptor-electron donor-electron acceptor) small molecules based on a commercial cyclopentadithiophene derivative have been synthesized for solution processed small molecule organic solar cells. The aim was to synthesise the molecules to be energetically identical (similar HOMO-LUMO energy levels) in order to assign the differences observed to changes in the film morphology or to differences in the interfacial recombination kinetics or both. Devices were electrically characterized under one sun simulated (1.

Diarylamino-substituted tetraarylethene (TAE) as an efficient and robust hole transport material for 11% methyl ammonium lead iodide perovskite solar cells.

We report the synthesis and characterisation of tetra{4-[N,N-(4,4'-dimethoxydiphenylamino)]phenyl}ethene () as an efficient and robust hole transport material for its application in methyl ammonium lead iodide (MAPI) perovskite solar cells. The solar cells show light-to-energy conversion efficiencies as high as 11.0% under standard measurement conditions without the need of additional dopants.