A generalizable reactive blending strategy to construct flame-retardant, mechanically-strong and toughened poly(L-lactic acid) bioplastics.

Poly(L-lactic acid) (PLA) is an environmentally-friendly bioplastic with high mechanical strength, but suffers from inherent flammability and poor toughness. Many tougheners have been reported for PLA, but their synthesis usually involves organic solvents, and they tend to dramatically reduce the mechanical strength and cannot settle the flammability matter. Herein, we develop strong, tough, and flame-retardant PLA composites by reactive blending PLA, 6-((double (2-hydroxyethyl) amino) methyl) dibenzo [c, e] [1,2] oxyphosphate acid 6-oxide (DHDP) and diphenylmethane diisocyanate (MDI) and define it PLA/xGH, where x indicates that the molar ratio of -NCO group in MDI to -OH group in PLA and DHDP is 1.0x: 1. This fabrication requires no solvents. PLA/2GH with a -NCO/-OH molar ratio of 1.02: 1 maintains high tensile strength of 63.0 MPa and achieves a 23.4 % increase in impact strength compared to PLA due to the incorporation of rigid polyurethane chain segment. The vertical combustion (UL-94) classification and limiting oxygen index (LOI) of PLA/2GH reaches V-0 and 29.8 %, respectively, because DHDP and MDI function in gas and condensed phases. This study displays a generalizable strategy to create flame-retardant bioplastics with great mechanical performances by the in-situ formation of P/N-containing polyurethane segment within PLA.

Chlorinated Narrow Bandgap Polymer Suppresses Non-Radiative Recombination Energy Loss Enabling Perylene Diimides-Based Organic Solar Cells Exceeding 10% Efficiency.

The scarcity of narrow bandgap donor polymers matched with perylene diimides (PDI)-based nonfullerene acceptors (NFAs) hinders improvement of the power conversion efficiency (PCE) value of organic solar cells (OSCs). Here, it is reported that a narrow bandgap donor polymer PDX, the chlorinated derivative of the famous polymer donor PTB7-Th, blended with PDI-based NFA boosts the PCE value exceeding 10%. The electroluminescent quantum efficiency of PDX-based OSCs is two orders of magnitude higher than that of PTB7-Th-based OSCs;therefore, the nonradiative energy loss is 0.103 eV lower. This is the highest PCE value for OSCs with the lowest energy loss using the blend of PTB7-Th derivatives and PDI-based NFAs as the active layer. Besides, PDX-based devices showed larger phase separation, faster charge mobilities, higher exciton dissociation probability, suppressed charge recombination, elevated charge transfer state, and decreased energetic disorder compared with the PTB7-Th-based OSCs. All these factors contribute to the simultaneously improved short circuit current density, open circuit voltage, and fill factor, thus significantly improving PCE. These results prove that chlorinated conjugated side thienyl groups can efficiently suppress the non-radiative energy loss and highlight the importance of fine-modifying or developing novel narrow bandgap polymers to further elevate the PCE value of PDI-based OSCs.

Efficient soluble PTCBI-type non-fullerene acceptor materials for organic solar cells.

Single perylene diimide (PDI) used as a non-fullerene acceptor (NFA) in organic solar cells (OSCs) is enticing because of its low cost and excellent stability. To improve the photovoltaic performance, it is vital to narrow the bandgap and regulate the stacking behavior. To address this challenge, we synthesize soluble perylenetetracarboxylic bisbenzimidazole (PTCBI) molecules with a bulky side chain at the bay region, by replacing the widely used "swallow tail" type alkyl chains at the imide position of PDI molecules with a planar benzimidazole structure. Compared with PDI molecules, PTCBI molecules exhibit red-shifted UV-vis absorption spectra with larger extinction coefficient, and one magnitude higher electron mobility. Finally, OSCs based on one soluble PTCBI-type NFA, namely MAS-7, exhibit a champion power conversion efficiency (PCE) of 4.34%, which is significantly higher than that of the corresponding PDI-based OSCs and is the highest PCE of PTCBI-based OSCs reported. These results highlight the potential of soluble PTCBI derivatives as NFAs in OSCs.

Flame-retardant poly(L-lactic acid) with enhanced UV protection and well-preserved mechanical properties by a furan-containing polyphosphoramide.

Despite good biodegradability and mechanical strength, the intrinsic flammability of poly(L-lactic acid) (PLA) impede its practical application. Introducing phosphoramide is an effective method to enhance the flame retardancy of PLA. However, most of the reported phosphoramides derive from petroleum resources, and their addition tends to deteriorate the mechanical properties, especially toughness, of PLA. Herein, a bio-based, furan-containing polyphosphoramide (DFDP) with high flame-retardant efficiency was synthesized for PLA. Our study found that 2 wt% DFDP enabled PLA to pass a UL-94 V-0 rating, and 4 wt% DFDP increased the limiting oxygen index (LOI) to 30.8 %. DFDP effectively maintained the mechanical strength and toughness of PLA. The tensile strength of PLA with 2 wt% DFDP reached 59.9 MPa, and its elongation at break and impact strength were increased by 15.8 % and 34.3 %, respectively, relative to those of virgin PLA. The UV protection of PLA was significantly enhanced by introducing DFDP. Hence, this work provides a sustainable and comprehensive strategy for the creation of flame-retardant biomaterials with improved UV protection and well-preserved mechanical properties, which possess a broad prospect in industrial application.

Hybrid Cycloalkyl-Alkyl Chain-Based Symmetric/Asymmetric Acceptors with Optimized Crystal Packing and Interfacial Exciton Properties for Efficient Organic Solar Cells.

Hybrid cycloalkyl-alkyl side chains are considered a unique composite side-chain system for the construction of novel organic semiconductor materials. However, there is a lack of fundamental understanding of the variations in the single-crystal structures as well as the optoelectronic and energetic properties generated by the introduction of hybrid side chains in electron acceptors. Herein, symmetric/asymmetric acceptors (Y-C10ch and A-C10ch) bearing bilateral and unilateral 10-cyclohexyldecyl are designed, synthesized, and compared with the symmetric acceptor 2,2'-((2Z,2'Z)-((12,13-bis(2-butyloctyl)-3,9 bis(ethylhexyl)-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″':4',5']thieno[2',3':4,5] pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10- diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (L8-BO). The stepwise introduction of 10-cyclohexyldecyl side chains decreases the optical bandgap, deepens the energy level, and enables the acceptor molecules to pack closely in a regular manner. Crystallographic analysis demonstrates that the 10-cyclohexyldecyl chain endows the acceptor with a more planar skeleton and enforces more compact 3D network packing, resulting in an active layer with higher domain purity. Moreover, the 10-cyclohexyldecyl chain affects the donor/acceptor interfacial energetics and accelerates exciton dissociation, enabling a power conversion efficiency (PCE) of >18% in the 2,2'-((2Z,2'Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″':4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (Y6) (PM6):A-C10ch-based organic solar cells (OSCs). Importantly, the incorporation of Y-C10ch as the third component of the PM6:L8-BO blend results in a higher PCE of 19.1%. The superior molecular packing behavior of the 10-cyclohexyldecyl side chain is highlighted here for the fabrication of high-performance OSCs.

High-efficiency organic solar cells processed from a real green solvent.

The fabrication of organic solar cells (OSCs) depends heavily on the use of highly toxic chlorinated solvents, which are incompatible with industrial manufacturing. The reported alternative solvents such as non-halogenated aromatic hydrocarbons and cyclic ethers are also not really "green" according to the "Globally Harmonized System of Classification and Labelling of Chemicals" of the United Nations. Therefore, processing from real green solvents such as water, alcohols, or anisole will constitute a big breakthrough for OSCs. However, it is fundamentally challenging to obtain high-performance photovoltaic materials processable from these solvents. Herein, we propose the incorporation of a B-N covalent bond, which has a dipole moment of 1.84 Debye, into the conjugated backbone of polymer donors to fabricate high-efficiency OSCs from anisole, a real green and eco-compatible solvent recommended by the United Nations. Based on a newly developed B-N-based polymer, the OSCs with a record-high efficiency of 15.65% in the 0.04 cm2 device and 14.01% in the 1.10 cm2 device have thus been realized via real green processing.

Novel Third Components with (Thio)barbituric Acid as the End Groups Improving the Efficiency of Ternary Solar Cells.

Developing novel third component is critical for the ternary organic solar cells (TOSCs). Herein, we design and synthesize two novel third components, MAZ-1 and MAZ-2, with 1,3-diethyl-2-thiobarbituric acid and 1,3-dimethylbarbituric acid as the weak electron withdrawing end groups, respectively. Both MAZ-1 and MAZ-2 could improve the photovoltaic performance of the binary OSCs based on D18:Y6 which exhibit the power conversion efficiency (PCE) of 17%, because the third components can optimize the phase separation, suppress the bimolecular recombination, and decrease the nonradiative energy loss in ternary blends. The PCE of the optimized TOSCs approaches 18% along with the simultaneous increase in open circuit voltage, short circuit current density, and fill factor by incorporating 10 wt % MAZ-1 and MAZ-2 in acceptors. This work enriches the building blocks for novel third components for achieving highly efficient TOSCs.

Adsorption-Catalysis-Conversion of Polysulfides in Sandwiched Ultrathin Ni(OH)2 -PANI for Stable Lithium-Sulfur Batteries.

Strong adsorption and catalysis for lithium polysulfides (LiPSs) are critical toward the electrochemical stability of Li-S batteries. Herein, a hollow sandwiched nanoparticle is put forward to enhance the adsorption-catalysis-conversion dynamic of sulfur species. The outer ultrathin Ni(OH)2 nanosheets not only confine LiPSs via both physical encapsulation and chemical adsorption, but also promote redox kinetics and accelerate the conversion of sulfur species, which is revealed by experiments and theoretical calculations. Meanwhile, the inner hollow polyaniline soft core provides a strong chemical bonding to LiPSs after vulcanization, which can chemically adsorpt LiPSs, and synergistically confine the shuttle effect. Moreover, the Ni(OH)2 nanosheets with a large specific area can enhance the wettability of electrolyte, and the flexible hollow sandwiched structure can accommodate the volume expansion, promoting sulfur utilization and structural stability. The obtained cathode exhibits excellent electrochemical performance with an initial discharge capacity of 1173 mAh g-1 and a small capacity decay of 0.08% per cycle even after 500 cycles at 0.2 C, among the best results of Ni(OH)2 -based materials for Li-S batteries. It is believed that the combination of adsorption-catalysis-conversion will shed a light on the development of cathode materials for stable Li-S batteries.

Using 3.0 eV Large Bandgap Conjugated Polymer as Host Donor to Construct Ternary Semi-Transparent Polymer Solar Cells: Increased Average Visible Transmittance and Modified Color Temperature.

Although optical engineering strategy has been utilized to optimize average visible transmittance (AVT) of semi-transparent organic solar cells (ST-OSCs), judicious selection of active layer materials should be more direct and basic. Herein, an efficient ternary active layer is constructed with a wide bandgap (3.0 eV) fluorescent polymer FC-S1 as host donor, a middle bandgap polymer PM6 as guest donor, and a narrow bandgap non-fullerene Y6-BO as acceptor. Using FC-S1 as the host donor can allow more visible photons to penetrate the device. In the absence of optical engineering, the ternary ST-OSC with FC-S1:PM6:Y6-BO = 1:0.3:1.5 active layer of 30 nm thickness displays a much higher AVT of 49.28% than that of 32.34% for a PM6:Y6-BO = 1.3:1.5 based binary ST-OSC. The ternary ST-OSC provides a good power conversion efficiency of 6.01%, only slightly lower than 7.15% for the binary ST-OSC. The ternary ST-OSC also demonstrates a color rendering index (CRI) of 87 and a correlated color temperature (CCT) of 6916 K, all better than CRI of 80 and CCT of 9022 K for the binary ST-OSC. Moreover, the backbone of FC-S1 is mainly composed by fluorene and carbazole, two easily-accessible aromatic rings, which would meet low-cost concern of ST-OSCs.

2,3-diaminophenazine as a high-rate rechargeable aqueous zinc-ion batteries cathode.

Organic materials are attracting extensive attention as promising cathodes for rechargeable aqueous zinc-ion batteries (ZIBs). However, most of them fail to implement the requirement of batteries with combined high-rate and long-cycle performance. Herein, we report a flexible organic molecule 2,3-diaminophenazine (DAP) which exhibits ultrahigh rate performance up to 500C and high capacity retention of 80% after 10,000 cycles at 100C (25.5 A g-1). Moreover, the Zn2+ storage mechanism in the DAP electrode is revealed by ex-situ characterization technologies and theoretical calculation, and the redox active centers CN participate in the reversible electrochemical reaction process. Furthermore, electrochemical analyses show that surface-controlled electrochemical behavior contributes to the high-rate performance of DAP cathodes. Besides, its excellent long-cycle performance can be ascribed to the suppressed DAP dissolubility by using a modified glass fiber separator with carbon nanotubes (CNT) film. Our work provides useful insight into the design of high-rate and long-life ZIBs.

Fine-Tuning the Dipole Moment of Asymmetric Non-Fullerene Acceptors Enabling Efficient and Stable Organic Solar Cells.

Modifying molecular conjugation has been demonstrated as an effective strategy to enhance the photovoltaic performance of the non-fullerene small molecule acceptors (SMAs), which would regulate the molecular packing and nanoscale morphology in the active layer of organic solar cells (OSCs). Here, two novel SMAs PTIC-4Cl and PT2IC-4Cl are designed and synthesized by expanding the core unit of TB-4Cl in one or two directions. The effects of how to expand the conjugation length on the absorption property, energy levels, dipole moment, and solubility are studied via theoretical calculation and experiments. Compared to PT2IC-4Cl, PTIC-4Cl with a more asymmetric structure exhibits the larger dipole moment and enhanced intermolecular packing. The PTIC-4Cl-based OSCs exhibit a favorable morphology and balanced charge transport, thereby leading to the highest power conversion efficiencies. In addition, PTIC-4Cl-based devices show outstanding thermal and air stability. These results reveal that fine-tuning the dipole moment via rationally expanding the conjugation in asymmetric A-D1A'D2-A-type non-fullerene acceptors is critical to achieve high-performance OSCs.

Characterization of Response Frequency for the Pressure-Sensitive Paint Based on Fluorine-Containing Polymer Matrixes Using Oscillating Sound Wave Technique.

Five kinds of new homo-polymer and copolymers of methacrylate containing a fluorine ester group were synthesized and used for the binder of pressure-sensitive paint (PSP)to ensure the good compatibility between luminophore (Pt(II) meso-tetra (pentafluorophenyl) porphine (PtTFPP)) and polymer binder. In the work, we were concerned with how the structure of thesepolymers containing fluorine, especially the various ester group structure, affects the response frequency of PSP using oscillating sound wave technique. The results showed that the pressure sensitivities (Sp) of these PSP samples containing different polymers, exhibit some difference. The length of ester chain on the methacrylatepolymer affects the response frequency of PSP sensor layer composed of the polymer. The longer the chain length of the ester group, the higher the response frequency of the PSP sensor layer quenching by oxygen.

Exfoliation and stabilization mechanism of graphene in carbon dioxide expanded organic solvents: molecular dynamics simulations.

CO2 expanded organic solvents possess significant advantages in liquid-phase exfoliation to obtain monolayer/few-layer graphene from graphite. Further insights into the mechanism of graphene exfoliation in such solvents are essential to explore liquid-phase dispersion of graphene as a more potent alternative to chemical vapor deposition. In this study, dynamic processes of exfoliation and stabilization of graphene in CO2-N,N-dimethylformamide (DMF), CO2-N-methylpyrrolidone (NMP), CO2-dimethyl sulfoxide (DMSO), and CO2-ethanol (EtOH) were investigated using molecular dynamics simulations. The origin of the effect of each solvent on graphene exfoliation was analyzed quantitatively through potential mean force simulations. It has been found that the organic solvent in a CO2 expanded solvent should be chosen with proper surface tension, and there exist two different graphene exfoliation processes in the effective solvents, which can be described as "burger dissociation" and "extrusion-taking away" processes, respectively. In the former process, a characteristic "super-burger-like" conformation with a semi-exfoliated structure was formed, which was the deciding factor to obtain high ratio of monolayer/few-layer graphene in dispersion product. A theoretical explanation has also been provided at the molecular level to the earlier experimental phenomena. A predicted simulation of the CO2-3,3'-iminobis(N,N-dimethylpropylamine) (DMPA) system is also calculated. This investigation helps to avoid incompatible CO2 expanded organic solvents employed in the experimental studies and provides theoretical clues to understand the mechanism of exfoliation and stabilization of graphene in such solvents.

Lead Selenide (PbSe) Colloidal Quantum Dot Solar Cells with >10% Efficiency.

Low-cost solution-processed lead chalcogenide colloidal quantum dots (CQDs) have garnered great attention in photovoltaic (PV) applications. In particular, lead selenide (PbSe) CQDs are regarded as attractive active absorbers in solar cells due to their high multiple-exciton generation and large exciton Bohr radius. However, their low air stability and occurrence of traps/defects during film formation restrict their further development. Air-stable PbSe CQDs are first synthesized through a cation exchange technique, followed by a solution-phase ligand exchange approach, and finally absorber films are prepared using a one-step spin-coating method. The best PV device fabricated using PbSe CQD inks exhibits a reproducible power conversion efficiency of 10.68%, 16% higher than the previous efficiency record (9.2%). Moreover, the device displays remarkably 40-day storage and 8 h illuminating stability. This novel strategy could provide an alternative route toward the use of PbSe CQDs in low-cost and high-performance infrared optoelectronic devices, such as infrared photodetectors and multijunction solar cells.

Chlorinated Wide-Bandgap Donor Polymer Enabling Annealing Free Nonfullerene Solar Cells with the Efficiency of 11.5.

Substituting the hydrogen atoms on the conjugated side chain of a wide-bandgap polymer J52 with chlorine atoms can simultaneously increase the Jsc, Voc, and FF of nonfullerene OSCs, leading to an efficiency boost from 3.78 to 11.53%, which is among the highest efficiencies for as-cast OSCs reported to date. To illustrate the impressive 3-fold PCE enhancement, the chlorination effect on the optical properties and energy levels of polymers, film morphology, and underlying charge dynamics is systematically investigated. Grazing incidence wide-angle X-ray scattering studies show that chlorinated J52-2Cl exhibits strong molecule aggregation, the preferred face-on orientation, and enhanced intermolecular π-π interactions, hence increasing the charge carrier mobility by 1 order of magnitude. Moreover, chlorination modifies the miscibility between the donor and acceptor and consequently optimizes the phase separation morphology of J52-2Cl:ITIC blend films. These results highlight chlorination as a promising approach to achieve highly efficient as-cast OSCs without any extra treatment.

Photoswitchable Self-Assembly/Disassembly of Near-Infrared Fluorophores.

A new photoswitchable near-infrared fluorophore (TDI-4DTE) with a symmetric structure exhibited reversible photo-controllable self-assembly and disassembly. The modification of π-conjugated terrylenediimide with four dithienylethene groups not only induced photoswitchable near-infrared fluorescence, but also photoregulated reversible precipitation-dissolution with microscopic and macroscopic polymorphism. Upon 302 nm UV-light irradiation, a noticeable precipitation was observed within seconds. The precipitate was gradually dissolved again in half an hour upon visible light irradiation. Different microscopic morphologies of the precipitates, including nanoparticles, nanofibrils and nanosheets, were observed when altering the intensity of the 302 nm light irradiation, indicating the dynamic control process of self-assembly. Upon UV-light irradiation, TDI-4DTE nanosheets were also obtained as a solid polymeric film, whereas well-defined nanoribbons with molecular monolayer thickness formed at the oil/water interface with slower assembly dynamics.

Controlled Synthesis of Carbon Nanospheres via the Modulation of the Hydrophilic Length of the Assembled Surfactant Micelles.

A co-polymerization-carbonization method was employed to synthesize porous carbon nanospheres (PCNSs) using pyrrole-aniline polymers as a carbon source and alkyl phenol non-ionic surfactants as templates. The effect of the hydrophilic length on the carbon nanosphere size was systematically investigated. The so-prepared PCNSs were characterized via high-magnification scanning electron microscopy, dynamic light scattering (DLS) analysis, and N2 adsorption and desorption analysis. The results indicate that the obtained nanosphere diameter can be tuned by changing the length of the hydrophilic groups. The length of the hydrophilic groups mainly affects the size of the vesicles or micelles formed by the assembly of the surfactant in solution, as was verified by the DLS results. After activation by KOH, the typical sample EO(30)-PCNS has a high specific surface area of 2137 m2/g and a large pore volume of 1.76 cm3/g. Electrochemical tests in 6 M KOH demonstrated that the assembled EO(30)-PCNS supercapacitor electrode displays good capacitive properties, such as a high specific capacitance of 221 F/g at 1.0 A/g and a good rate capacity of 68% retention at 10.0 A/g. This finding suggests that the uniform particle shape and high specific surface area are beneficial for the ion transportation, leading to good electrochemical performances. Our work provides a novel synthetic strategy for the fabrication of carbon nanospheres or other nanosphere materials for the construction of high-performance supercapacitors by optimizing few parameters, such as the length of the hydrophilic or hydrophobic groups of the surfactants.

3D Synergistical MXene/Reduced Graphene Oxide Aerogel for a Piezoresistive Sensor.

A piezoresistive sensor based on ultralight and superelastic aerogel is reported to fabricate MXene/reduced graphene oxide (MX/rGO) hybrid 3D structures and utilize their pressure-sensitive characteristics. The MX/rGO aerogel not only combines the rGO's large specific surface area and the MXene's (Ti3C2 T x) high conductivity but also exhibits rich porous structure, which leads to performance better than that of single-component rGO or MXene in terms of the pressure sensor. The large nanosheets of rGO can prevent the poor oxidization of MXene by wrapping MXene inside the aerogel. More importantly, the piezoresistive sensor based on the MX/rGO aerogel shows extremely high sensitivity (22.56 kPa-1), fast response time (<200 ms), and good stability over 10 000 cycles. The piezoresistive sensor based on the MX/rGO hybrid 3D aerogel can easily capture the signal below 10 Pa, thus clearly testing the pulse of an adult at random. Based on its superior performance, it also demonstrates potential applications in measuring pressure distribution, distinguishing subtle strain, and monitoring healthy activity.

Piezoresistive Pressure Sensor Based on Synergistical Innerconnect Polyvinyl Alcohol Nanowires/Wrinkled Graphene Film.

Piezoresistive sensor is a promising pressure sensor due to its attractive advantages including uncomplicated signal collection, simple manufacture, economical and practical characteristics. Here, a flexible and highly sensitive pressure sensor based on wrinkled graphene film (WGF)/innerconnected polyvinyl alcohol (PVA) nanowires/interdigital electrodes is fabricated. Due to the synergistic effect between WGF and innerconnected PVA nanowires, the as-prepared pressure sensor realizes a high sensitivity of 28.34 kPa-1 . In addition, the device is able to discern lightweight rice about 22.4 mg (≈2.24 Pa) and shows excellent durability and reliability after 6000 repeated loading and unloading cycles. What is more, the device can detect subtle pulse beat and monitor various human movement behaviors in real-time.

5,6-Difluorobenzothiazole-Based Conjugated Polymers with Large Band Gaps and Deep Highest Occupied Molecular Orbital Levels.

A 5,6-difluorobenzothiazole-based dibromo monomer was successfully synthesized, from which new fluorinated conjugated polymers PF-ffBTz and PFN-ffBTz were prepared via copolymerizations with two fluorene-based diboronic ester monomers. Twisted fluorene-ffBTz backbones enable PF-ffBTz and PFN-ffBTz with large band gaps up to 3.10 eV and deep-lying highest occupied molecular orbital levels down to -6.2 eV. The chemical structures of PF-ffBTz and PFN-ffBTz impart some new functionalities of fluorinated conjugated polymers. PF-ffBTz can show deep blue electroluminescent emission, with high external quantum efficiency of 3.71%. PFN-ffBTz, with amino-functionalized side chains on the fluorene unit, can serve as an efficient cathode interlayer in inverted polymer solar cells (PSCs), showing better photovoltaic performances if compared with a ZnO interlayer. In addition, it is found that using an optical filter to cut off the short wavelength section (≤380 nm) of incident light can significantly elevate photostability of PSCs under continuous illumination.