Efficient Non‐Fullerene Organic Photovoltaic Modules Incorporating As‐Cast and Thickness‐Insensitive Photoactive Layers

Abstract

In this work, a new combination of a wide bandgap polymer poly[4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b:4,5‐b′]‐dithiophene‐alt‐N‐(2‐hexyldecyl)‐5′5‐bis[3‐(decylthio)thiophene‐2‐yl]‐2′2‐bithiophene‐3′3‐dicarboximide] (PBTIBDTT) and a non‐fullerene small molecule acceptor based on a bulky seven‐ring fused core (indacenodithieno[3,2‐b]thiophene) end‐capped with 2‐(3‐oxo‐2,3‐dihydroinden‐1‐ylidene)malononitrile groups with one fluorine substituent (ITIC‐F) is proposed, and as‐cast non‐fullerene organic solar cells (NFOSCs) with 11.2% efficiency are achieved. The device efficiencies are also insensitive to the variation of photoactive layer (PAL) thickness and can maintain over 9% efficiency as PAL thickness increases to 350 nm, which is one of the best results for as‐cast organic solar cells. More importantly, non‐fullerene organic photovoltaic (OPV) modules are demonstrated via laser ablation technique for the first time, which delivers a record efficiency of 8.6% (with active area of 3.48 cm2) among large‐area OPV modules. Furthermore, the morphology and performance evolutions of the as‐cast NFOSCs and the ones processed with solvent additive are systematically investigated. The results demonstrate the great advantage of as‐cast solar cells in achieving constant morphology and high performance with thick PALs. The NFOSCs fabricated with simple procedure, insensitive to film thickness and compatible with large‐area OPV modules, show significant potential for application the future.

Chlorine Effects of Heterocyclic Ring‐Based Donor Polymer for Low‐Cost and High‐Performance Nonfullerene Polymer Solar Cells

“…As shown in Figure e,f, in the films of the pristine polymers, the (100) and (010) distances for P(Cl) became closer to 1.0 and 0.07 Å, respectively, closer than the equivalent values for P(Th). Considering the films of the polymer blended with ITIC‐Th, P(Cl):ITIC‐Th also retained a high degree of lamellar packing and π—π stacking to a greater extent than P(Th):ITIC‐Th, and the (100) and (010) distances in the former film were closer at 2.23 and 0.01 Å, respectively . Considering the (100) and (200) peaks, which demonstrated the crystallinity of ITIC‐Th, we can conclude that P(Cl):ITIC‐Th has a longer‐range packing order than P(Th):ITIC‐Th; the (100) distance becomes as small as 0.05 Å, and the (200) peak is seen only for P(Cl):ITIC‐Th, taking a distance of 6.37 Å .…”

“…The performances of the devices gradually increased for up to 167 and 246 h, respectively, at which point the maximum PCEs were observed (without encapsulation: PCE = 11.3%, V oc = 0.899 V, J sc = 18.5 mA cm −2 , and FF = 67.6%; with encapsulation: PCE = 11.4%, V oc = 0.899 V, J sc = 18.6 mA cm −2 , and FF = 68.1%). We believe that the cause of this increase is the relaxation of the tilting generated by the presence of large Cl atoms in the polymer backbone; both devices have closer inter‐/intramolecular packing order than their initial states . Moreover, surprisingly, the PCEs of the cells without and with encapsulation retain 91% and 101% of their initial values for up to 2002 and 2858 h, respectively.…”

Evaporation‐Free Nonfullerene Flexible Organic Solar Cell Modules Manufactured by An All‐Solution Process

“…Furthermore, as seen from the GIWAXS data, ITIC-Th had lower crystallinity than ITIC ( Figure S9e,f, Supporting Information). [23,46,56,70] To compare the compatibility the donor polymer and NFA components, the surface tension (γ) was determined and calculated from the contact angles measured using two solvents, water (distilled water) and oil (diiodomethane, DIM) in each pristine film ( Figure S11 and Table S4, Supporting Information). Therefore, it was inferred that ITIC would be more compatible with PBDB-T, which has lower crystallinity, while ITIC-Th would be more compatible with SMD2, which has higher crystallinity.…”

“…[1][2][3][4][5][6] It is possible to design high-performance devices by designing photoactive materials that constitute a bulk heterojunction (BHJ), [7][8][9] device engineering, [10][11][12][13] and a combination of these. [4,[16][17][18][19][20] Recently, different methods such as spin coating, [21][22][23] slotdie coating, [24][25][26] and blade coating, [27,28] are being attempted to develop large-area modules with laboratory-to-industrial applications. [4,[16][17][18][19][20] Recently, different methods such as spin coating, [21][22][23] slotdie coating, [24][25][26] and blade coating, [27,28] are being attempted to develop large-area modules with laboratory-to-industrial applications.…”

“…Among them, slot-die coating can easily control each layer and the related processing factors, such as discharge rate and speed, thus enabling control of thickness and conformation. [32,33] Several particular challenges need to be considered in the manufacturing of this type of OSC modules using an R2R process; these included thermally treating the film [34,35] and ensuring the thermal stability of the substrate [36] the uniformity of the film morphology, [22][23][24] and the evaporation process of the buffer layer and the electrode. [16,29] Krebs and co-workers fabricated flexible OSC modules using a roll-to-roll (R2R) manufacturing process called "ProcessOne."…”