Enhancement of photovoltaic performance of solvent-free dye-sensitized solar cells with doped poly(3-hexylthiophene)

Effects of Ti3C2Tx MXene Addition to a Co Complex/Ionic Liquid-Based Electrolyte on the Photovoltaic Performance of Solar Cells

“…Furthermore, a shift in the TiO 2 ’s CBE could be estimated from the dark current curves of the DSCs [ 29 , 30 , 31 ]. Figure 4 presents the dark current–voltage curves of the bare and Ti 3 C 2 T x -Co- b DSCs.…”

“…Another method to estimate electron lifetime in cells is open-circuit voltage decay (OCVD) measurements. Using the results of OCVD measurements [Figure 7a] and Equation (11), where k B is the Boltzmann constant, T is the temperature, e is the electron charge, and dV oc /dt is the derivative of the V oc transient [30,31,36], we could calculate the electron lifetime (τ) of the bare and Ti 3 C 2 T x -Cob DSCs. As shown in Figure 7b, the electron lifetimes recorded for the Ti 3 C 2 T x -Cob DSC were shorter than those for the reference cell (bare Cob DSC), which suggests that the incorporation of the MXene boosted the BET reaction between the photoinjected electrons and the redox mediators.…”

“…The R3 values, named as Warburg diffusion resistance (Ws) arising from the ionic transport in the redox mediator [28], were almost similar in both the bare (6.79 Ω) and Ti3C2Tx-Co-bDSCs (6.24 Ω), indicating that the presence of Ti3C2Tx MXene in the redox mediator did not hinder the diffusion of the Co 2+ /Co 3+ redox couple. Furthermore, a shift in the TiO 2 's CBE could be estimated from the dark current curves of the DSCs [29][30][31]. Figure 4 (∆E MXene ) between the dye's lowest unoccupied molecular orbital level (LUMO) and the TiO 2 's CBE in the Ti 3 C 2 T x -Cob DSC was larger than that (∆E Bare ) in the bare Cob DSC (i.e, ∆E Bare < ∆E MXene in Figure 5), thereby resulting in an improvement in the electron injection efficiency [32].…”