All‐Polymer Solar Cells with over 12% Efficiency and a Small Voltage Loss Enabled by a Polymer Acceptor Based on an Extended Fused Ring Core

Abstract

Although the field of all‐polymer solar cells (all‐PSCs) has seen rapid progress in device efficiencies during the past few years, there are limited choices of polymer acceptors that exhibit strong absorption in the near‐IR region and achieve high open‐circuit voltage (VOC) at the same time. In this paper, an all‐PSC device is demonstrated with a 12.06% efficiency based on a new polymer acceptor (named PT‐IDTTIC) that exhibits strong absorption (maximum absorption coefficient: 2.41 × 105 cm−1) and a narrow optical bandgap (1.49 eV). Compared to previously reported polymer acceptors such as those based on the indacenodithiophene (IDT) core, the indacenodithienothiophene (IDTT) core has further extended fused ring, providing the polymer with extended absorption into the near‐IR region and also increases the electron mobility of the polymer. By blending PT‐IDTTIC with the donor polymer, PM6, a high‐efficiency all‐PSC is achieved with a small voltage loss of 0.52 V, without sacrificing JSC and FF, which demonstrates the great potential of high‐performance all‐PSCs.

On the energy gap determination of organic optoelectronic materials: the case of porphyrin derivatives

“…For a couple of decades, organic semiconductors (OS) have been extensively investigated as candidate materials for optoelectronic devices such as field-effect transistors (OFETs) [1][2][3][4] , light-emitting devices (OLEDs) [5][6][7][8][9][10] , photovoltaics (OPVs) [11][12][13][14][15][16][17] and more recently for solar-fuel production [18][19][20][21][22][23] and energy storage such as Lithium-ion batteries (LIB). [24][25][26][27][28][29] OS are very appealing thanks to several intrinsic characteristics of organic materials viz.…”

Regio‐Regular Polymer Acceptors Enabled by Determined Fluorination on End Groups for All‐Polymer Solar Cells with 15.2 % Efficiency

“…[27][28][29][30][31] Regarding these issues,L ia nd co-workers first proposed an effective approach by adopting SMAs as the acceptor units to construct high-performance donor-acceptor (D-A) polymer acceptors, [32] which significantly improves the PCEs of all-PSCs owing to the higher absorption coefficient, broader photon response range and better complementary spectra with donor polymers in multiple cases. [33][34][35] Subsequently,encouraged by the rapid progress of Y-series SMAs, the efficiencies of all-PSCs consisting of an ovel polymer acceptor,PY-T, have been optimized to over 13 %. [36,37] These results demonstrate that SMA-polymerization is an effective approach, but most research has concentrated on the modifications of the Dunits and the side chains of the SMAs as the comonomers (Figure S2).…”

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

“…Recently, inspired by the success of Y-series SMAs, the PCEs of all-PSCs comprising a novel polymer acceptor called PY-T have been increased to over 13% with a more extended absorption to the near-infrared region and reduced energy loss. [32,33] Although all-PSCs have made great progress in recent years, most of the research focuses on the manipulation of π bridges and the substitution of the core in monomer SMAs ( Figure S2, Supporting Information), [34][35][36] and there is no report on the end group modification. In fact, fluorination of the end groups in the A-D-A type SMAs has already been proved to be a successful strategy to improve J SC , intermolecular aggregation and thus device performance.…”