Efficient Small‐Molecule Organic Solar Cells by Modulating Fluorine Substitution Position of Donor Material

Abstract

Comprehensive SummaryThe fluorine substitution position in organic semiconductors is critical in improving device performance for organic solar cells (OSCs). Herein, two similar small‐molecule donors, B3T‐PoF and B3T‐PmF, are designed and synthesized, which only differ on the fluorine substitution position on the pendent benzene unit. Although both small‐molecule donors exhibit similar absorption profiles and molecular energy levels, B3T‐PmF has stronger crystallinity and lower energetic disorder than B3T‐PoF. After blending with the non‐fullerene acceptor of BO‐4Cl, B3T‐PmF shows better phase separation and more ordered molecular packing in blend film. As a result, the B3T‐PoF:BO‐4Cl‐based OSC shows a power conversion efficiency (PCE) of 12.3%. In contrast, the B3T‐PmF:BO‐4Cl‐based cell demonstrates obviously increased JSC and FF values, thus yielding an excellent PCE of 14.7%. This study indicates that reasonable selection of fluorine atom substitution position in conjugated side chains is one of the promising strategies for achieving high‐performance SM‐OSCs.

Pyrrole‐Based Fully Non‐fused Acceptor for Efficient and Stable Organic Solar Cells

“…Organic solar cells (OSCs) have garnered widespread attention due to their advantages, including flexibility, lightweight and highly tunable light-absorption properties. [1][2][3][4][5][6][7][8][9] Advances in photovoltaic materials and device engineering have propelled the power conversion efficiency (PCE) of single-junction OSCs to exceeded 19 %. [3,[10][11][12][13][14][15][16] Nevertheless, the limitations posed by inherent properties of organic semiconductors, including low charge transport characteristics, impose constraints on the achievable thickness of the photoactive layer.…”

“…Organic solar cells (OSCs) have garnered widespread attention due to their advantages, including flexibility, lightweight and highly tunable light‐absorption properties [1–9] . Advances in photovoltaic materials and device engineering have propelled the power conversion efficiency (PCE) of single‐junction OSCs to exceeded 19 % [3,10–16] .…”

Pyrrole‐Based Fully Non‐fused Acceptor for Efficient and Stable Organic Solar Cells

“…Organic solar cells (OSCs) have garnered widespread attention due to their advantages, including flexibility, lightweight and highly tunable light-absorption properties. [1][2][3][4][5][6][7][8][9] Advances in photovoltaic materials and device engineering have propelled the power conversion efficiency (PCE) of single-junction OSCs to exceeded 19 %. [3,[10][11][12][13][14][15][16] Nevertheless, the limitations posed by inherent properties of organic semiconductors, including low charge transport characteristics, impose constraints on the achievable thickness of the photoactive layer.…”

“…Organic solar cells (OSCs) have garnered widespread attention due to their advantages, including flexibility, lightweight and highly tunable light‐absorption properties [1–9] . Advances in photovoltaic materials and device engineering have propelled the power conversion efficiency (PCE) of single‐junction OSCs to exceeded 19 % [3,10–16] .…”

Enhancing Electroluminescence of Medium‐Gap Organic Photovoltaic Cells Through the Incorporation of Pyrrole Rings in Acceptors

“…Organic photovoltaic (OPV) cells are characterized by their tunable absorption, flexibility, absence of heavy metals, and lightweight. [1][2][3][4][5] With the rapid development of non-fullerene acceptors (NFAs), the photovoltaic performance of OPV cells has been steadily breaking through. [6][7][8][9][10][11] Currently, the power conversion efficiencies (PCEs) of singlejunction OPV cells have approached 20%.…”