Blade-Coated All-Polymer Organic Solar Cells with 15% Efficiency Using Eco-Friendly Solvent Systems.

18.55% Efficiency Polymer Solar Cells Based on a Small Molecule Acceptor with Alkylthienyl Outer Side Chains and a Low-Cost Polymer Donor PTQ10

Enhancing the Intermolecular Interactions of Ladder-Type Heteroheptacene-Based Nonfullerene Acceptors for Efficient Polymer Solar Cells by Incorporating Asymmetric Side Chains

Here, we show that flexible perovskite solar cells (PSCs) with high operational stability and power conversion efficiency (PCE) approaching 20% were achieved by elastic grain boundary (GB) encapsul...

Surfactant-Encapsulated Polyoxometalate Complex as a Cathode Interlayer for Nonfullerene Polymer Solar Cells

The development of readily accessible polymer acceptors is imperative to preserve the guiding principles of all-polymer solar cells as a low-cost and sustainable technology for alternative energy production. In this study, we report a computationally guided design and facile synthesis of new acceptor polymers comprising the alternating copolymer, PNIT, and the corresponding random copolymer, r-PNIT, which incorporate structurally simple naphthalene diimide (NDI) and isoindigo (IID) units. PNIT was prepared via direct arylation polymerization (DArP), which proceeds via C–H activation and avoids the use of toxic reagents and extended synthetic pathways for the monomer synthesis. PNIT has broad optical absorption in the 300–850 nm range and an enhanced absorption coefficient (47 × 103 cm–1) compared to r-PNIT (300–850 nm; 40 × 103 cm–1). When incorporated in all-polymer solar cells (APSCs) using PBDB-T as the donor polymer, PBDB-T:PNIT provides greater than two times the average (maximum) power conversion efficiency (PCE) of 5.18 ± 0.08 (5.32)% compared to that of PBDB-T:r-PNIT, 2.38 ± 0.16 (2.57)%, due to increased Jsc (10.36 vs 5.45 mA cm–2) and fill factor (FF) (0.58 vs 0.50) metrics. The PBDB-T:PNIT PCE is among the highest reported for an IID-based APSC and demonstrates the viability of DArP for the synthesis of new APSC acceptor polymers. Detailed morphological and microstructural investigations using atomic force microscopy (AFM) and grazing-incidence wide-angle X-ray scattering (GIWAXS), respectively, reveal enhanced texturing for PNIT, which enhances charge transport properties as supported by space-charge-limited current (SCLC) mobility measurements.

Oligothiophene-based photovoltaic materials for organic solar cells: rise, plateau, and revival

Near-Infrared All-Fused-Ring Nonfullerene Acceptors Achieving an Optimal Efficiency-Cost-Stability Balance in Organic Solar Cells

Cold Crystallization Temperature Correlated Phase Separation, Performance, and Stability of Polymer Solar Cells

<i>D</i> ^{6 <i>h</i>} Symmetric Radical Donor–Acceptor Nanographene Modulated Interfacial Carrier Transfer for High-Performance Perovskite Solar Cells

Systematic Investigation of Solution-State Aggregation Effect on Electrical Conductivity in Doped Conjugated Polymers

We report the improved performance of all-polymer solar cells with bulk heterojunction nanolayers of an electron-donating polymer (poly(3-hexylthiophene) (P3HT)) and an electron-accepting polymer (poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT)), which were both doped with 4-ethylbenzenesulfonic acid (EBSA). To choose the doping ratio of P3HT for all-polymer solar cells, various EBSA doping ratios (0, 1, 3, 5, 10, 20 wt%) were tested by employing optical absorption spectroscopy, photoluminescence spectroscopy, photoelectron yield spectroscopy, and space-charge-limited current (SCLC) mobility measurement. The doping reaction of P3HT with EBSA was followed by observing the colour change in solutions. The final doping ratio for P3HT was chosen as 1 wt% from the best hole mobility measured in the thickness direction, while that for F8BT was fixed as 10 wt% (F8BT-EBSA). The polymer:polymer solar cells with bulk heterojunction nanolayers of P3HT-EBSA (EBSA-doped P3HT) and F8BT-EBSA (EBSA-doped F8BT) showed greatly improved short circuit current density (J(SC)) and open circuit voltage (V(OC)), compared to the undoped solar cells. As a result, the power conversion efficiency (PCE) was enhanced by ca. 300% for the 6 : 4 (P3HT-EBSA : F8BT-EBSA) composition and ca. 400% for the 8 : 2 composition. The synchrotron-radiation grazing incidence angle X-ray diffraction (GIXD) measurement revealed that the crystallinity of the doped nanolayers significantly increased by EBSA doping owing to the formation of advanced phase segregation morphology, as supported by the surface morphology change measured by atomic force microscopy. Thus the improved PCE can be attributed to the enhanced charge transport by the formation of permanent charges and better charge percolation paths by EBSA doping.

High-performance donor–acceptor electron acceptors containing 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (INCN)-type terminals are labile toward photooxidation and basic conditions, and ...

An octyloxy substituted benzofurazan based poly(carbazole-alt-thiophene-benzofurazan) (PCzDTBF) was synthesized by Suzuki polycondensation. The absorption spectra of the polymer were peaked at 385 and 540 nm, and the HOMO and LUMO energy levels were −5.34 and −3.46 eV, respectively. The hole mobility was found to be 4.8 × 10−4 cm2 V−1 S−1 by the space charge limited current (SCLC) method, and the surface energy (Es) was calculated to be 35.8 mJ m−2 from the contact-angle measurement. Polymer solar cells (PSCs) based on the blend of PCzDTBF and PCBM with a weight ratio of 1 : 2 were fabricated. The devices were found to have a power conversion efficiency (PCE) of 4.2% in the device configuration of ITO/PSS:PEDOT/PCzDTBF:PC70BM/Al. By utilizing poly[(9,9-dioctyl-2,7-fluorene)-alt-(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)] (PFN) as the cathode interfacial layer, the PCE was enhanced to 5.48%, with an open-circuit voltage (Voc) of 0.90 V, a short-circuit current density (Jsc) of 7.73 mA cm−2, and a fill factor (FF) of 67%. The high efficiencies could be ascribed to the good morphology, resulting from the matched surface energies of the PCzDTBF and PCBM components, and the distinct enhancement on Voc and FF by the PFN layer, where it is possible that a built-in field potential exists between the active layer and cathode.

Recent progress of all-polymer solar cells – From chemical structure and device physics to photovoltaic performance

Bulk heterojunction polymer solar cells based on a novel combination of materials are fabricated using industry‐compliant conditions for large area manufacturing. The relatively low‐cost polymer PTQ10 is paired with the nonfullerene acceptor 4TIC‐4F. Devices are processed using a nonhalogenated solvent to comply with industrial usage in absence of any thermal treatment to minimize the energy footprint of the fabrication. No solvent additive is used. Adding the well‐known and low‐cost fullerene derivative PC61BM acceptor to this binary blend to form a ternary blend, the power conversion efficiency (PCE) is improved from 8.4% to 9.9% due to increased fill factor (FF) and open‐circuit voltage (VOC) while simultaneously improving the stability. The introduction of PC61BM is able to balance the hole–electron mobility in the ternary blends, which is favourable for high FF. This charge transport behavior is correlated with the bulk heterojunction (BHJ) morphology deduced from grazing‐incidence wide‐angle X‐ray scattering (GIWAXS), atomic force microscopy (AFM), and surface energy analysis. In addition, the industrial figure of merit (i‐FOM) of this ternary blend is found to increase drastically upon addition of PC61BM due to an increased performance–stability–cost balance.