- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Investigation on voltage loss in organic triplet photovoltaic devices based on Ir complexes
摘要： Voltage losses in singlet material-based organic photovoltaic devices (OPVs) have been intensively studied, whereas, only a few investigations on triplet material-based OPVs (T-OPVs) are reported. To investigate the voltage loss in T-OPVs, two homoleptic iridium(III) complexes based on extended p-conjugated benzo[g]phthalazine ligands, Ir(Ftbpa)3 and Ir(FOtbpa)3, are synthesized as sole electron donors. T-OPVs are fabricated by mixing two donors with phenyl-C71-butyric acid methyl ester (PC71BM) as an electron acceptor. Insertion of oxygen-bridges as flexible inert d-spacers in Ir(FOtbpa)3 has slightly elevated both the lowest unoccupied molecular orbital and the highest occupied molecular orbital levels compared to those of Ir(Ftbpa)3, which results in a lower charge transfer (CT) state energy (ECT) for Ir(FOtbpa)3-based devices. However, a higher Voc (0.88 V) is observed for Ir(FOtbpa)3-based devices than those of Ir(Ftbpa)3 (0.80 V). To understand the above result, the morphologies of the two blend films are studied, which excludes the influence of morphology. Furthermore, radiative and non-radiative recombination in two devices is quantitatively investigated, which suggests that a higher Voc can be attributed to reduced radiative and non-radiative recombination loss for the Ir(FOtbpa)3-based devices.
关键词： charge transfer state energy,organic photovoltaic devices,triplet material-based OPVs,radiative and non-radiative recombination,iridium(III) complexes,voltage loss
更新于2025-09-12 10:27:22
-
Energetic Disorder and Activation Energy in Efficient Ternary Organic Solar Cells with Nonfullerene Acceptor Eh‐IDTBR as the Third Component
摘要： Solution processed ternary organic solar cells (OSCs) contain a third component in the active layer besides the donor/acceptor materials. Two main avenues are considered to fabricate ternary OSCs: (i) to improve the short circuit current density by the selected third component that can broaden and/or enhance the absorption of the host films; (ii) to increase the fill factor by adding materials with diverse crystallinity to tune the film morphology. However, little work has been reported for the improvement of open circuit voltage (VOC), energetic disorder, charge transfer state energy (ECT), and activation energy in ternary OSCs. Herein, we used ternary OSCs with active layer composed of PCE10: F8IC: Eh-IDTBR as model to examine these parameters besides the morphology. We found in the ternary device that the additional Eh-IDTBR improved the crystallinity of the acceptor phase in the ternary mixture; the VOC was 58 mV higher than that of the reference caused by the reduced energetic disorder; due to the good miscibility of Eh-IDTBR with both PCE10 and F8IC, only 50 meV in ECT was observed; zero field activation energy was lower than that for the reference. Our findings provide an alternative way to understand the complex ternary structural-electrical properties correlations.
关键词： ternary organic solar cells,charge transfer state energy,crystallinity phase,energetic disorder,activation energy
更新于2025-09-11 14:15:04