A liquid-crystalline non-fullerene acceptor enabling high-performance organic solar cells

Abstract

The flexibility of the additional sidechains of 4TICO allows the material to reorganise itself upon annealing, leading to higher solar cell performance.

Tailoring the charge transport characteristics in ordered small-molecule organic semiconductors by side-chain engineering and fluorine substitution

“…The solution-processable OSMs exhibited strong intermolecular interactions that are favourable for achieving high-quality films with optimal morphology, and hence, high charge carrier mobility. 12,13 Due to slow crystallization, the films based on OSMs exhibited large defect-free domains with a lower density of grain boundaries, which act as traps for charge carriers. 14,15 Previously, we showed that unsubstituted thiophene (T)benzothiadiazole (B) pentamer TBTBT is a promising semiconductor material for organic electronic devices.…”

“…H NMR (CDCl 3 , 500 MHz, d): 8.17 (s, 2H), 7.94 (s, 2H), 2.65 (d, 4H, J = 6.76 Hz), 2.49 (t, 4H, J 1 = 7.85 Hz, J 2 = 8.05 Hz), 1.59 (m, 6H), 1.39-1.28 (m, 36H), 0.90 (m, 18H) ppm;13 C NMR (CDCl 3 , 126 MHz, d): 148.76, 148.69, 143.12, 139.46, 134.71, 132.95, 130.40, 127.48, 112.32, 112.23, 110.14, 110.04, 41.70, 32.63, 32.19, 31.95, 30.89, 29.71, 29.55, 29.37, 28.89, 28.34, 25.73, 23.09, 22.73, 14.18, 14.15, 10.87 ppm; 19F NMR (CDCl 3 , 470 MHz, d): À126.27, À129.01 ppm. FT-IR (KBr, n): 3850, 3730, 2957, 2924, 2853, 1622, 1516, 1480, 1455, 1426, 1378, 1332, 1298, 1207, 1150, 1082, 1026, 1004, 891, 851, 801cm À1 .…”

Ternary Organic Solar Cells with Binary Additives Finely Regulated Active Layer Morphology and Improved Photovoltaic Performance

“…Photo‐CELIV provides a rare technology to characterize charge transport in real working photovoltaic devices with low‐mobility materials, and this method has been widely used in the study of OSCs. [ 3,46,47 ] In photo‐CELIV measurement, free charge carriers are generated by a light pulse and then subsequently extracted by a voltage ramp. [ 48 ] When the charge carriers are extracted from the OSCs, a current overshoot occurs ( j max is the peak current and j disp is the displacement current).…”

Understanding the role of non-fullerene acceptor crystallinity in the charge transport properties and performance of organic solar cells

“…The analysis of the main Bragg peaks of the NFA, oen referred to as the lamellar (100) and the p-p stacking (010) distances, [34][35][36] is routinely considered enough to draw conclusions. Misleading results can, however, arise from the similar (if not overlapping) spectral features of the donor and acceptor components in the q-space, the typical peak broadening of organic compound isomers, polymorphism, 37,38 and a general lack of long-range crystalline order. 35 In this work, we used an extensive set of both experimental and theoretical approaches to study the molecular packing and morphology of a specic set of common NFAs (o-IDTBR, IDIC, ITIC, m-ITIC, 4TIC, 4TICO, and m-4TICO, whose structures are shown in Fig.…”