Three-Dimensional Observation of a Light-Soaked Photoreactant Layer in BTR:PCBM Solar Cells Treated with/without Solvent Vapor Annealing

Abstract

A key challenge to the commercialization of solution-processed solar cells is a proper understanding of the morphological variations during long periods, particularly under light-soaking conditions. Many research groups have competitively reported solvent vapor annealing (SVA)-treated small-molecule devices with efficiency rates exceeding 11%; however, their light-soaking effects have been rarely studied. Here, we investigate the morphological changes in the light-soaked devices with/without SVA treatments depending on the illumination time via three-dimensional observations. From the results, we found that the trends of morphological variations differ in the surface and bulk parts of the active film and that the difference is closely related to the device performance capabilities. Therefore, our research will enhance the underlying knowledge of the light-soaking effect on active morphologies over long term.

Perfect Complementary in Absorption Spectra with Fullerene, Nonfullerene Acceptors and Medium Band Gap Donor for High-Performance Ternary Polymer Solar Cells

“…The changes after the ternary blending occur in plane, and the characteristic peaks of both the acceptors are preserved. This crystallinity of the molecules with changes in the order of molecular packing ensures efficient electronic transmission. − These results reveal that the judicious selection of the acceptor pairs in ternary blends can further improve the performance of OSCs through the complementary absorption of sunlight. In addition, the active layer morphology of the ternary blends can be tuned by varying the ratio of acceptors.…”

Efficient DMSO-Vapor Annealing for Enhancing Thermoelectric Performance of PEDOT:PSS-Based Aerogel

“…Compared to highly conductive PEDOT:PSS thin films, these as-prepared PEDOT:PSS aerogels have low σ and S values, which are desired to be improved further for a good TE material despite of a low κ value. As we know, organic solvent post-treatment has been widely used to improve the σ of PEDOT:PSS films (>1000 S cm –1 ). , Recently, solvent vapor annealing (VA) has been developed and confirmed to be an efficient method on improvement of performance for organic solar cells − and TE materials. − Compared to solvent immersion, vapor annealing is more suitable for PEDOT:PSS-based aerogel materials. First, aerogel with porous network is favorable to facilitate the diffusion of solvent molecule and keep good morphology structure.…”

Bicomponent Random Approach for the Synthesis of Donor Polymers for Efficient All-Polymer Solar Cells Processed from A Green Solvent

“…As D–A molar ratio >1, random polymers show broaden (100) diffraction and increased π–π stacking distance, which indicate that random copolymerization could break the intermolecular packing structure along the alkyl side chain and π–π stacking structure. The coherence lengths ( L c ) of the crystalline domains were determined from fwhm (full-width-at-half-maximum) values of the diffraction peaks using the Scherrer equation and are listed in Table . , The largest L c (100) and L c (010) values are estimated for the PBDT–TPD film. As partially replacinghe the A (TPD) unit with t D (BDT) unit, the decreased L c (100) values in PBDT a –TPD b are observed, while the L c (100) values exhibit the following order: PBDT 8 –TPD 7 > PBDT 4 –TPD 1 > PBDT 5 –TPD 4 > PBDT 3 –TPD 2 > PBDT 2 –TPD 1 .…”

“…The coherence lengths (L c ) of the crystalline domains were determined from fwhm (full-width-athalf-maximum) values of the diffraction peaks using the Scherrer equation and are listed in Table 3. 66,67 The largest L c (100) and L c (010) values are estimated for the PBDT−TPD film. As partially replacinghe the A (TPD) unit with t D (BDT) unit, the decreased L c (100) values in PBDT a −TPD b are observed, while the L c (100) values exhibit the following order: PBDT 8 −TPD 7 > PBDT 4 −TPD 1 > PBDT 5 −TPD 4 > PBDT 3 −TPD 2 > PBDT 2 −TPD 1 .…”