Exploiting Ternary Blends to Accurately Control the Coloration of Semitransparent, Non‐Fullerene, Organic Solar Cells

Abstract

Semitransparent organic solar cells (STOSCs) have received increasing attention due to promising applications such as building‐integrated photovoltaics. Successful commercialization requires that STOSCs are aesthetically pleasing as well as having balanced power conversion efficiencies (PCEs) and average visible transmittances (AVTs). Non‐fullerene acceptors, which possess excellent electrical/chemical properties, have helped STOSCs to achieve high PCE and AVT; however, research related to modulating color and appearance of STOSCs has lagged behind. Herein, narrow bandgap donor and acceptor (PTB7‐Th and IEICO‐4F) and ultra‐wide bandgap acceptors (T2‐ORH and T2‐OEHRH) are used to achieve semitransparency and controllable device coloration. Blend films with controllable colors including cyan → blue → purple → reddish purple colors are successfully demonstrated, which are controlled by ratios of IEICO‐4F:T2‐ORH or IEICO‐4F:T2‐OEHRH with PTB7‐Th. By incorporating semitransparent electrodes (comprising Sb2O3/Ag/Sb2O3), STOSCs with PCEs of 6–7% are achieved for cyan, aqua, indigo, and purple and ≈4% PCEs for reddish‐purple colors, with AVTs in the range of 23–35%. Moreover, optical properties of blend films are studied via absorption and transmission measurements, whereas the range of colors achieved is quantified using commission internationale de l'éclairage (CIE) chromaticity and CIE L * a * b* color space then represented as RGB color models.

Ternary Polymer Solar Cells Enabled Using Two Donor Polymers with Broad Absorption and Cascade LUMO Levels

“…The absorption spectrum of blend films is shown in Figure c, which is consistent with the EQE curve. The J SC calculated by integrating EQE spectra (23.72, 25.15, and 23.93 mA cm –2 for the three types of PSCs) is slightly smaller than the measured J SC (24.45, 25.93, and 24.54 mA cm –2 for the three types of PSCs, respectively, and the deviation was less than a 3% error). , …”

“…The J SC calculated by integrating EQE spectra (23.72, 25.15, and 23.93 mA cm −2 for the three types of PSCs) is slightly smaller than the measured J SC (24.45, 25.93, and 24.54 mA cm −2 for the three types of PSCs, respectively, and the deviation was less than a 3% error). 25,26 In comparison with the J SC value, along with the increased PTB7-Th content, the ternary PSCs exhibited a decreased V OC value. Under light irradiation, the photogenerated electrons on the LUMO of the donor may prefer to transfer to the LUMO of the acceptor according to the LUMO level offsets between the donor and acceptor and transport at the acceptor domain and hole transport at the donor domain.…”

Photopically Transparent Organic Solar Cells with Tungsten Oxide-Based Multilayer Electrodes

“…Referring to the APT-dependent LUE of the full device configuration, our work recorded the highest LUE (3.27%) and notable transparency (46.7%) of the device. Figure d and Table S1 compare the results achieved in this work with the reported T-OSC results (PTB7-Th:IEICO-4F-based T-OSCs only). ,− In addition, another important factor in the evaluation of the performance of T-OSCs is the International Commission on Illumination (CIE) coordinates, which are related to color perception by the human eye. Another crucial point is that the CIE coordinates should be close to the white point (0.3333, 0.3333), which results in good achromatic or neutral color perception under AM1.5G illumination .…”

Donor–Acceptor Alternating Copolymer Compatibilizers for Thermally Stable, Mechanically Robust, and High-Performance Organic Solar Cells

“…The maximum absorption wavelength (λ max ) values of PBDB-T, Y10-Br, and PBDTY5-Cl were 621, 746, and 804 nm, respectively. Thus, PBDB-T and Y10-Br showed complementary absorption, and PBDTY5-Cl extended the absorption of the binary blend into the 900 nm regime, enhancing light harvesting. − …”