Solution-processed polymer solar cells (PSCs) have attracted dramatically increasing attention over the past few decades owing to their advantages of low cost, solution processability, light weight, and excellent flexibility. Recent progress in materials synthesis and devices engineering has boosted the power conversion efficiency (PCE) of single-junction PSCs over 17%. As an emerging technology, it is still a challenge to prepare solution-processed flexible electrodes for attractive flexible PSCs. Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) is one of the most promising candidates for electrodes due to its high conductivity (>4000 S/cm), excellent transmittance (>90%), intrinsically high work function (W_F > 5.0 eV), and aqueous solution processability. To date, a great number of single-junction PSCs based on PEDOT:PSS electrodes have realized a PCE over 12%. In this review, we introduce the current research on the conductive complex PEDOT:PSS as well as trace the development of PEDOT:PSS used in electrodes for high performance PSCs and perovskite solar cells. We also discuss and comment on the aspects of conductivity, transmittance, work-function adjustment, film preparing methods, and device fabrications. A perspective on the challenges and future directions in this field is be offered finally.

Herein, we report a flexible high-conductivity transparent electrode (denoted as S-PH1000), based on conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), and itsapplication to flexible semi-transparentsupercapacitors. A high conductivity of 2673 S/cm was achieved for the S-PH1000 electrode on flexible plastic substrates via a H₂SO₄ treatment with an optimized concentration of 80 wt.%. This is among the top electrical conductivities of PEDOT:PSS films processed on flexible substrates. As for the electrochemical properties,a high specific capacitance of 161F/g was obtained from the S-PH1000 electrode at a current density of 1 A/g. Excitingly, a specific capacitance of 121 F/g was retained even when the current density increased to 100 A/g, which demonstrates the high-rate property of this electrode. Flexible semi-transparent supercapacitors based on these electrodes demonstrate high transparency, over 60%, at 550 nm. A high power density value, over 19,200 W/kg,and energy density, over 3.40 Wh/kg, was achieved. The semi-transparent flexible supercapacitor was successfully applied topower a light-emitting diode.

Plastic electrodes are desirable for the rapid development of flexible organic electronics. In this article, a plastic electrode has been prepared by employing traditional conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and plastic substrate polyethersulfone (PES). The completed electrode (Denote as HC-PEDOT:PSS) treated by 80% concentrated sulfuric acid (H₂SO₄) possesses a high electrical conductivity of over 2673 S/cm and a high transmittance of over 90% at 550 nm. The high conductivity is attributed to the regular arrangement of PEDOT molecules, which has been proved by the X-ray diffraction characterization. Temperature-dependent conductivity measurement reveals that the HC-PEDOT:PSS possesses both semiconducting and metallic properties. The binding force and effects between the PEDOT and PEI are investigated in detail. All plastic solar cells with a classical device structure of PES/HC-PEDOT:PSS/PEI/P3HT:ICBA/EG-PEDOT:PSS show a PCE of 4.05%. The ITO-free device with a structure of Glass/HC-PEDOT:PSS/Al4083/PM6:Y6/PDINO/Ag delivers an open-circuit voltage (V_OC) of 0.81 V, short-circuit current (J_SC ) of 23.5 mA/cm², fill factor (FF) of 0.67 and a moderate power conversion efficiency (PCE) of 12.8%. The above results demonstrate the HC-PEDOT:PSS electrode is a promising candidate for all-plastic solar cells and ITO-free organic solar cells.

A unique conducting polymer intercalation strategy is developed to optimize the ion/electron transport of V₂O₅ based aqueous zinc-ion batteries (ZIBs). It presents a new tactic to construct a high-performance and durable ZIB cathode.

Flexible organic solar cells (FOSCs) have gained significant attention as a promising power source for wearable electronics. PEDOT:PSS is a commonly used functional layer material in FOSCs due to its excellent light transparency and electrical conductivity, especially suitable for interface and electrode materials. However, PEDOT:PSS has poor phase separation, resulting in a rough surface that is unfavorable for contact between upper and lower layers, as well as poor mechanical properties. Herein, we optimize the neutral mechanical plane based on strain isolation and investigate the mechanism of using the poly(TA-DIB-Fe) intermediate protective layer to improve the mechanical properties of PEDOT:PSS layers and FOSCs. The interface design is applied to transparent electrodes on a 25 cm² substrate to prepare ultra-flexible modules with a power conversion efficiency (PCE) of more than 14%. The mechanical stability evaluation of the crumpled, thin, and lightweight large-area module is conducted for the first time. The PCE loss is less than 5% after 1000 cycles of bending, and the module maintains good operational performance after crumpling tests. This study presents a novel theory and method for enhancing the tenacity of flexible electronics and provides scientific guidance for the large-scale application of wearable electronics.

POEAX (X = I, Br, Cl) parallel dipole engineering simultaneously passivates defects and modulates interfaces in wide-bandgap perovskite solar cells, achieving 19.54% efficiency and enabling all-perovskite tandem solar cells with 28.92% efficiency.