Selective Hole and Electron Transport in Efficient Quaternary Blend Organic Solar Cells

Abstract

Quaternary organic solar cells (q-OSCs) achieve a power conversion efficiency (PCE) of 17.73%, which is by far the highest reported PCE to date for q-OSCs. The quaternary devices significantly outperform the corresponding binary and ternary devices with various material combinations displaying the enormous potential of the quaternary blend system through rational design. We demonstrated a new type of ''rivers and streams'' hierarchical morphology that allows for the achievement of highly efficient quaternary devices that were considered extremely challenging in the past.

Modulation of Morphological, Mechanical, and Photovoltaic Properties of Ternary Organic Photovoltaic Blends for Optimum Operation

“…This is consistent with recent soft X‐ray scattering work that shows the development of small PC 71 BM domains in PM6:PTQ10:Y6 ternaries with the addition of PC 71 BM. [ 49 ] To attain a more quantitative comparison of their phase‐separated morphology, we plotted the power spectral density (PSD) profiles in Figure 4f by performing Fourier transform analysis [ 50–52 ] of the TEM images. The characteristic length scale of PM6:N3 phase separation (center to center distance of N3 rich domains) was determined from the spatial frequency at which the Lorentz‐corrected intensity reaches a maximum.…”

“…This finding will enable the prediction of the elastic modulus of various kinds of ternary blends being widely used in the OPV field and might be further applied to nearly 18%‐efficiency quaternary blend OPVs with a “rivers and streams”‐type morphology. [ 49 ] The possibility to finely tune the film morphology via complete control of the ink formulations opens up new ways to fabricate organic/polymeric semi‐conducting blend films with desired electrical and mechanical properties.…”

Thermodynamic Properties and Molecular Packing Explain Performance and Processing Procedures of Three D18:NFA Organic Solar Cells

“…[18] Some of the fundamental information of this new material in neat and blended forms, such as molecular ordering, packing and texture, and thermodynamic properties still remain to be revealed and characterized. Additionally, ternary or quaternary blending is often a successful way to improve the performance of some binary OSCs, [19][20][21][22] a path unexplored for D18based devices.…”

Fluorinated End Group Enables High‐Performance All‐Polymer Solar Cells with Near‐Infrared Absorption and Enhanced Device Efficiency over 14%

“…[ 1–7 ] Through the various strategies including molecular modulation on small‐molecular acceptors (SMAs), morphology optimization and interfacial engineering, the bulk‐heterojunction devices based on polymer donors and SMAs have realized impressive power conversion efficiencies (PCEs) over 17%. [ 8–14 ] Among these achievements, Y6‐series SMAs, which feature an A′‐DAD‐A′ structure, have demonstrated multiple cases of high‐performance PSCs with optimized morphology and low energy loss. [ 15–17 ]…”