NiO/ZrO₂ nanocomposites as photocathodes of tandem DSCs with higher photoconversion efficiency with respect to parent single-photoelectrode p-DSCs

Abstract

Tandem dye-sensitized solar cell shows higher photoconversion performances with respect to parent devices with single photoactive electrode thanks to careful photocurrent matching and complementarity of electrodes optical absorption.

In Situ Construction of Metal–Organic Frameworks as Smart Channels for the Effective Electrocatalytic Reduction of Nitrate at Ultralow Concentrations to Ammonia

“…The core level spectrum for pristine UiO shows four peaks. The peaks located at binding energies (BEs) of 183.0 and 185.3 eV correspond to the Zr (+4) oxidation state in Zr 6 O 4 (OH) 4 (BDC) 6 . ,, Another doublet of peaks centered at 182.7 and 185.0 eV should be assigned to the Zr suboxide (+3). , Interestingly, the Zr 3d peaks of UiO-CuZn exhibit a higher oxidation state after the incorporation of the CuZn nanocluster (Zr 4+ /(Zr 4+ + Zr 3+ ) ratios are 43.1% and 76.2% for pristine UiO and UiO-CuZn, respectively), indicating a decrease in the electron density of Zr species. As plotted in Figure S8a in the Cu 2p region, the two peaks at binding energies (BEs) of 932.9 and 952.8 eV should be assigned to Cu 2p 3/2 and Cu 2p 1/2 , respectively.…”

Pentafluorosulfanyl-functionalised BODIPY push–pull dyes for p-type dye-sensitized solar cells

“…The structure of the dye should be, in future, modified to raise the energy of the frontier electronic orbitals to drive charge-separation and reduce the HOMO-LUMO energy gap to shift the absorption further towards the NIR. 8 Expansion of the BODIPY core to increase conjugation may enhance the absorption coefficient and light harvesting efficiency, enabling more photocurrent to be generated by the photocathode. 19 Adding bulky substituents around the core may help to protect the NiO from the electrolyte and increase the voltage.…”

“…9 The dyes that have been applied in p-DSSCs include perylene diimides, squaraines, diketopyrrolopyrrole, quinones, pyranbased systems, porphyrins, triphenylamine donor-p linkeracceptor structures, and combinations of these. 2,3,8 The pushpull dye P1 is generally considered to be a good benchmark, due to optimised short circuit current density (J SC ) = 5.47 mA cm −2 , incident photon to conversion efficiency (IPCE) = ca. 63%, and power conversion efficiency (PCE) of 0.16% with I 3 − /I − electrolyte.…”

“…7 Alternatively, the photocathode could be sensitized with a dye absorbing shorter wavelengths as used as the top electrode and an NIR dye could be used to sensitize the photoanode at the bottom. 8 As with conventional DSSCs, the criteria for the dye are a high molar absorption coefficient and suitable redox potentials which straddle the valence band of the p-type material in the photocathode and the redox potential of the electrolyte to drive charge separation. Much work has been devoted to developing dyes for TiO 2 .…”

P1 Push‐Pull Dye as a Case Study in QM/MM Theoretical Characterization for Dye‐sensitized Solar Cell Organic Chromophores**

“…Generally, the efficiency of p-type cells is remarkably lower than that of n-type [38][39][40] and it is related to the possibility of charge recombination (between holes in the semiconductor and the reduced dye or the reduced form of the redox mediator) [41][42][43] and/or of dye aggregation (with an intermolecular charge transfer, thus decreasing the effectiveness of the electron injection between the semiconductor and the dye molecules).…”