Increasing the Open-Circuit Voltage of Dye-Sensitized Solar Cells via Metal-Ion Coordination

Abstract

Considerable efforts are dedicated to increasing the open-circuit voltage (V) of dye-sensitized solar cells (DSSCs) by slowing charge recombination dynamics using atomic layer deposition, alkyl-substituted dyes, coadsorbents, and other strategies. In this report, we introduce metal-ion coordination to a metal oxide bound dye as an alternative means of increasing V. Metal-ion coordination has minimal influence on the photophysical and electrochemical properties of the N3 dye, but presumably because of increased steric hindrance at the interface, it slows charge recombination kinetics and increases V by upwards of 130 mV relative to the parent N3 DSSC. With respect to the nature of the metal ion, the trend in decreasing short-circuit current (J) and increasing V correlates with the charge of the coordinated metal ion (M → M → M). We attribute this trend to electrostatic interactions between the metal cation and I or I, with the more highly charged cations maintaining a higher concentration of mediator anions in proximity to the surface and, as a result, increasing the regeneration and recombination rates.

Engineering Band‐Type Alignment in CsPbBr3 Perovskite‐Based Artificial Multiple Quantum Wells

“…The boost in the V oc of the type-II MQW versus its type-I sisters by ≈110 and 270 mV is attributed to the slowed carrier recombination dynamics in the former. [40,41] Such a superior photovoltaic effect in the CsPbBr 3 /BCP MQWs relative to that observed in the bulk CsPbBr 3 and the two type-I MQWs correlates well with the longer electron-hole recombination lifetime possessed by the type-II MQWs (see Figure 5). Moreover, the RR, i.e., a figure of merit for collating the efficacy of rectification, [34,39] was also calculated for the four devices.…”

Fabrication of a counter electrode for dye-sensitized solar cells (DSSCs) using a carbon material produced with the organic ligand 2-methyl-8-hydroxyquinolinol (Mq)

“…This may be attributed to electrostatic interactions between the carbon atom and I À or I 3 À , and a higher concentration of mediator anions in proximity to the carbon surface, resulting in the increase of the regeneration and recombination rates. 87,88 The lower ll factor and J sc are responsible for the poor efficiency. Even though a higher catalytic activity was observed in the electrode fabricated using the produced carbon due to the highly porous lm offering a higher effective surface area for the reduction of triiodide species, the resistance of the lm or higher overpotential towards the redox reaction appears to be the dominating factor in deciding the cell performance.…”

Towards implementing hierarchical porous zeolitic imidazolate frameworks in dye-sensitized solar cells

“…The change of the shape of the IPCE spectrum for L1Fc@ZIF-8 may point to morphological alterations in the light absorbing dye due to encapsulation. It is not clear if the low performance of the systems in this study is caused by the low dye loading or due to the absence of direct electron injection mechanisms from the dye to the metal oxide substrate [46,47]. The Nyquist plot of L1Fc@ZIF-8 shows a very high resistance for the encapsulated dye as compared to the free dye L1Fc (287 Ω) [6], due to the low conductivity of ZIF-8 (electronic supplementary material, figure S11).…”