Synergetic Effect of Different Carrier Dynamics in Pm6:Y6:ITIC-M Ternary Cascade Energy Level System

Abstract

Although reported ternary polymer solar cells have higher power conversion efficiency than binary polymers, the mechanism of exciton separation and charge transport in this complex ternary system is still unclear. Herein, based on PM6:Y6:ITIC-M ternary solar cells, we combine the technique of luminescence spectroscopy, including electroluminescence (EL) and photoluminescence (PL) with photovoltaic measurements, to understand clearly the detailed roles of ITIC-M as the third component in the contribution of device performance. The results show that ITIC-M can form the alloy-like composite with Y6 but leave individual Y6 acceptor to conduct charge transfer with PM6 donor, which improves Voc but decreases Jsc because of poor charge transfer capacity of ITIC-M. Meanwhile, the energy transfer from PM6 to ITIC-M exists in the active layers; small IE suppresses exciton dissociation. Deteriorating performance of solar cells demonstrates that, except for complementary absorption spectrum and suitable energy levels in PM6:Y6:ITIC-M system, the synergetic effects of carrier dynamics among different organic materials play an important role in influencing the performance of ternary solar cells.

Dual-Functional Enantiomeric Compounds as Hole-Transporting Materials and Interfacial Layers in Perovskite Solar Cells

“…We used the most common approach to calculate the trap density from the so-called trap-filled-limit voltage: where V TFL is the trap-filled-limit voltage, e is the elementary charge, L is the thickness of the active layer, ε is the relative dielectric constant of perovskite, ε 0 is the vacuum permittivity, and n t is the trapping state density (eq ). …”

Improving the performance of ternary organic solar cells using metal oxides as charge-transport layers

“…As shown in Table S2 (ESI†), the 16.6–16.8% PCEs are similar to those (16.52–16.86%) for OSCs using the PM6:IDIC:Y6 active layers reported in previous studies. 27,36 Even compared with other PM6-based ternary OSCs, our devices showed a comparable or medium PCE level among these values (see Table S2, ESI†). The PCE difference under the forward and reverse scans is only 1.2%, indicating a small hysteresis degree of the OSC.…”

Improved Light Soaking and Thermal Stability of Organic Solar Cells by Robust Interfacial Modification

“…The enhanced electron transport and extraction in modified ZnO devices were further supported by the dependence of photocurrent density J ph ( J ph = J light – J dark , where J light and J dark are the current density under 1.5 AM illumination and darkness, respectively) versus effective voltage V eff ( V eff = V O – V appl , where V O is the voltage at J ph equal to zero and V appl is the applied voltage) characteristics (Figure 3c). [ 52 ] The exciton dissociation probability, P ( E , T ), in OSCs was obtained from the normalized value of J ph with respect to the saturated current density ( J sat ) ( J ph / J sat ) under short‐circuit conditions. P ( E , T ) values, which are related to the charge transfer efficiency, were found to be 95.5%, 97.4%, and 97.2%, for devices incorporating ZnO, ZnO/SAR, and ZnO/OCS, respectively.…”