”Face-On” Oriented ^|^pi;-Conjugated Polymers Containing 1,3,4-Thiadiazole Moiety Investigated with Synchrotron GIXS Measurements: Relationship between Morphology and PSC Performance

Abstract

The detailed morphology was investigated on 1,3,4-oxadiazole (OXD) and 1,3,4-thiadiazole (TD) containing -conjugated polymer films based on synchrotron GIXS measurements.Grazing-incidence wide-angle X-ray scattering (GIWAXS) proved that TD-containing polymers showed face-on orientation, which is, in general, favor for the polymer solar cell (PSC) application. Density function theory calculation suggests that the favorable orientation is probably induced by the curvature of TD-containing polymer main chains. In addition, the bulk-heterojunction structure were evaluated by grazing-incidence small-angle X-ray scattering (GISAXS) and atomic force microscope (AFM). As a result, it was also found that the - stacking distance, correlation length and PC 61 BM cluster size had good relationship with the short circuit current density (J sc ) and fill factor (FF) in the PSC application.

2,2′-Bis(1,3,4-thiadiazole)-Based π-Conjugated Copolymers for Organic Photovoltaics with Exceeding 8% and Its Molecular Weight Dependence of Device Performance

“…There is only one report on a BTDz-based small molecule for a light-emitting diode application, but the OPV performance and film morphology of the BTDz-based polymers have never been reported. Although mono-1,3,4-thiadiazole (TD)-containing semiconducting polymers have also been developed, − the OPV characteristics were limited, probably due to their poor coplanar structures. Similar to TzTz, BTDz has a rigid and planar backbone without hydrogen atoms at 3,4-positions to improve intermolecular packing.…”

Regioisomeric thieno[3,4-d]thiazole-based A-Q-D-Q-A-type NIR acceptors for efficient non-fullerene organic solar cells

“…CCL/d calculation helps to estimate the periodicity of a material's packing over a certain distance and its value is correlated to the average number of lamellas in the L length. 53 TzS-S (CCL/d = 6.86) has higher periodicity than TzN-S (CCL/d = 4.72) in the π–π direction, resulting in higher charge carrier mobilities in the blend film. The low carrier mobilities within PCE10:TzN-S is attributed to the large crystalline grain (CCL = 1.454 nm) since exciton dissociation interface decreases with the domain size increased.…”

“…CCL/d calculation helps to estimate the periodicity of a material's packing over a certain distance and its value is correlated to the average number of lamellas in the L length. 53 TzS-S (CCL/d = 6.86) has higher periodicity than TzN-S (CCL/d = 4.72) in the p-p direction, resulting in higher charge carrier mobilities in the blend lm.…”