Fully Coated Semitransparent Organic Solar Cells with a Doctor-Blade-Coated Composite Anode Buffer Layer of Phosphomolybdic Acid and PEDOT:PSS and a Spray-Coated Silver Nanowire Top Electrode

Abstract

In the aim to realize high performance semitransparent fully coated organic solar cells, printable electrode buffer layers and top electrodes are two important key technologies. An ideal ink for the preparation of the electrode buffer layer for printed top electrodes should have good wettability and negligible solvent corrosion to the underlying layer. This work reports a novel organic-inorganic composite of phosphomolybdic acid (PMA) and PEDOT:PSS that features excellent wettability with the active layer and printed top Ag nanowires and high resistibility to solvent corrosion. This composite buffer layer can be easily deposited on a polymer surface to form a smooth, homogeneous film via spin-coating or doctor-blade coating. Through the use of this composite anode buffer layer, fully coated semitransparent devices with doctor-blade-coated functional layers and spray-coated Ag nanowire top electrodes showed the highest power conversion efficiency (PCE) of 5.01% with an excellent average visible-light transmittance (AVT) of 50.3%, demonstrating superior overall characteristics with a comparable performance to and a much higher AVT than cells based on a thermally evaporated MoO/Ag/MoO thin film electrode (with a PCE of 5.77% and AVT of 19.5%). The current work reports the fabrication of fully coated inverted organic solar cells by combining doctor-blade coating and spray coating and, more importantly, demonstrates that a nanocomposite of a polyoxometalate and conjugated polymer could be an excellent anode buffer layer for the fully coated polymer solar cells with favorable interfacial contact, hole extraction efficiency, and high comparability with full printing.

Highly Efficient Nonfullerene Organic Photovoltaic Devices with 10% Power Conversion Efficiency Enabled by a Fine‐Tuned and Solution‐Processed Hole‐Transporting Layer

“…[ 14,17,30 ] Currently, the best polymer donor reported for collocating NFAs requires an extremely deep highest occupied molecular orbital ( HOMO ) level that is more negative than −5.4 eV to maximize the built‐in voltage of devices. [ 9–11,16,17,31 ] The low HOMO level of the active layer therefore forms a massive energy barrier between the HOMO of the electron donor and the work function (WF) of PEDOT:PSS (WF ≈ −5.0 eV is mostly reported in the literature), [ 32–34 ] which results in the poor electrical performance of inverted devices. Nevertheless, only a few studies have reported an inverted OPV device using an NF‐based BHJ layer with an alternative solution‐processed HTL for industrial module production.…”

High‐Efficiency Nonfullerene Organic Solar Cells Enabled by Atomic Layer Deposited Zirconium‐Doped Zinc Oxide

“…At a low voltage bias, traps in the active layer can respond to the modulated signal, whereas at a high voltage bias, the trap state can suppress the response. [ 98,99 ] The Nyquist plots from EIS measurements are shown in Figure 15b. These plots were fitted with an equivalent electrical circuit, which is shown in Figure 15b for analysis.…”

Solution‐Processable Anode Double Buffer Layers for Inverted Polymer Solar Cells

“…Encouraged by these findings, the approach reported by Ji et al was attempted. Thus, 0.8 mL of PEDOT388, 0.1 mL of MoPMo solution, and 0.1 mL of isopropanol have been mixed and used as a composite deposited by spin coating.…”

“…This issue is commonly not tackled in the routine laboratory‐scale practice, thus it is essential to stress the importance of a thick HTL for practical applications. Interestingly, either molybdenum salts, molybdenum oxide nanoparticles, or Mo‐polyoxometallates have also been mixed with PEDOT:PSS to provide hybrid buffer layers. Inverted polymer solar cells show efficiencies comparable with e‐MoO x and satisfactory stability …”