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A core–shell structure material of silicon/nickel oxide nanosheets provides huge potential for high efficiency and long-term stability of metal halide perovskite solar cells.

The inclusion of BCA molecules in SnO2 improves film coverage of ETL, regulates energy level, increases electron transport and migration ability, and enhances crystallization of perovskite. Overall, PSCs fabricated in open-air achieve a champion efficiency of 20.24%.

This work synthesized a hydrazone dye with a carbonyl and pyrazolone structure and benzene ring to passivate defects, significantly improving the perovskite solar cell's efficiency and stability.

In this paper, an ionic liquid (BMIMHSO4) was used to regulate the TiO2/perovskite interface. The interfacial interaction makes the BMIMHSO4 a connection in TiO2 and perovskite layers, providing high-efficiency electron extraction and thus improving device performance.

The TFEMA dimers formed via an in situ polymerization strategy can passivate defects and tune energy band alignment. The PSCs fabricated under open air conditions achieve a champion efficiency of 20.18% with enhanced moisture and thermal stability.

In this work, we synthesized a dye molecule, HQTh-EC, and used it as an interlayer to reduce trap density and to improve charge transport, achieving a PCE of 20.08% for planar PSCs with negligible hysteresis under air conditions without a glovebox.

In recent years, organic-inorganic halide perovskite solar cells (PSCs) have attracted massive attention because of their high power conversion efficiency (PCE). However, it is difficult to prepare perovskite films with good performance in open air due to the poor stability of perovskite materials in high humidity, which is seriously hindering the practical application and development of PSCs. Herein, ethyl acetate (EA) is introduced into the perovskite precursor to enhance the crystallinity of perovskite for fabricating high efficiency stable devices in the atmospheric environment. Interestingly, volatile EA, which is often used as an anti-solvent, could quickly evaporate and accelerate the nuclei formation during perovskite crystallization. More impressively, the Lewis base nature of EA can form strong chemical bonding interactions with perovskite to passivate the defects during crystallization. As a result, the EA-modified perovskite film demonstrates dense and defect-less morphology with large grain size (the maximum achieves 0.9 μm). The EA-treated device has a dramatic efficiency of 19.53% and negligible hysteresis of the photocurrent. Furthermore, both the temperature and humidity resistances of EA-modified PSC are significantly improved. The normalized PCE of the EA-modified device without encapsulation can still retain over 80% of its initial value after being stored in 60% relative humidity (RH) in the dark for 500 hours. This contribution provides a promising channel for facilitating the commercialization of PSCs.

Integrating a proper amount of polymer hybrid of quaternary ammonium chloride functionalized graphitic carbon nitride (PHQACl-CN) in the perovskite leads to positive adjustments in the morphology of the treated perovskite films and boosts the PSC device performance.

A typical solution-processed perovskite film possesses numerous defects, especially when fabricated under high-humidity ambient conditions, which severely limits the performance of planar perovskite solar cells (PSCs). Here, the unique fluorescent dye molecule additive of 3-(2-benzimidazolyl)-7-(diethylamino)-coumarin (8GFF) is introduced into a perovskite film to address the defect issues. With the addition of 8GFF, its functional groups (–COO) can interact with Pb2+ ions, thereby minimizing the ionic defects in the perovskite film and improving its crystalline quality. And the optimized charge transport with decreased recombination loss can also be realized. Besides, the introduction of 8GFF increases the absorption capacity of the device in a green light wave band, beneficial for photocurrent enhancement. Consequently, the device fabricated in an air environment without a glove box exhibits a promising efficiency of 19.16%, superior to 15.61% of the control device. This work demonstrates the potential applications for fabricating high-performance planar devices regarding the aspects of fluorescent dyes.

The crystallinity of a perovskite film can play a key role in the photovoltaic performance and long-term stability of perovskite solar cells (PSCs). Herein, we introduce 4-tert-butylpyridine (tBP) into perovskite on the reduction-active poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hole transport layer and maximize its morphology-regulating effect via enhancing the concentration of CH3NH3I used in the two-step spin-coating. Since the high concentration iodine methylamine increases the oxidation potential, a perovskite film with large grains can be obtained. Furthermore, we proposed using a small amount of tBP with a high concentration of CH3NH3I and found that it would form a gradient structure in the perovskite. A small amount of tBP in CH3NH3I can further enhance its diffusion mobility into PbI2 films. Moreover, tBP in perovskite with a gradient structure can further induce coordination between tBP and perovskite, leading to considerably large perovskite grains (∼1.4 μm) with defect-free morphology. The perovskite grains can be more completely surrounded by the stronger hydrophobic tBP. Therefore, both the efficiencies and moisture stabilities of the PSCs can be significantly enhanced. PSCs without encapsulation could even maintain more than 80% of their initial PCE after 400 h of moisture exposure (RH ∼50%). Moreover, the flexible devices after optimization could achieve a PCE of 14.92%, and still maintain at 11.39% after 20 times of mechanical bending.

Organometallic halide perovskite solar cells (PSCs) with a high power conversion efficiency (PCE) have attracted immense attention for applications and commercialization. Nevertheless, it is still a challenge to find a novel method to overcome the rapid degradation of the perovskite so that PSCs demonstrating an excellent performance can be fabricated in an ambient environment without a glove box. Herein, in this paper, triethyl phosphate (TEP) is introduced into the perovskite layer via antisolvent engineering to serve as a crystallization aid and a humidity stabilizer. Impressively, the electron-rich phosphate group in TEP can form a strong chemical bonding interaction with the perovskite (Pb–O) to passivate the defects produced during crystallization. More interestingly, the ethyl group with its hydrophobic effect can protect the perovskite film from corrosion by the moisture in the air. As a result, the TEP-modified perovskite film demonstrates a dense and defectless morphology with a large grain size (a maximum of more than 1 μm). The TEP-treated device achieves a dramatic efficiency of 19.6% and negligible hysteresis of the photocurrent. Moreover, the humidity resistance of the TEP-modified device is significantly enhanced. The normalized PCE of the TEP-modified device (unencapsulated) can still retain 82% of its initial value after being stored in an 85% humidity environment under dark conditions for 400 hours. This finding provides a promising approach for facilitating the commercialization of PSCs.

Inorganic p-type semiconductors have broadly served as hole transport materials (HTLs) in perovskite solar cells (PSCs) in recent years. Among them, NiCo2O4 with its excellent conductivity and hole mobility is the emerging candidate for HTLs and is attracting increasing attention. Here, we employ a simple hydrothermal method to fabricate high-quality mesoporous NiCo2O4 films as HTLs of PSCs. The study finds that the morphology of NiCo2O4 can be regulated from nanosheets (NSs) to nanowires (NWs) as the hydrothermal reaction time increases, and the morphology of NiCo2O4 significantly affects the device performance. Specially, the device with NWs achieves a best efficiency of 11.58%, ascribed to the fact that such a one dimension material could provide a straight path for hole extraction/transport. And benefiting from the mesoporous structures of NiCo2O4 films, all the devices exhibited a very repeatable and desirable long-term stability. Overall, this work develops alternative NiCo2O4 nanostructure-based HTLs and opens up new opportunities in fabricating PSCs.

This study aimed to evaluate the compatibility of L. acidophilus KLDS 1.0738 (LA-1.0738) with different prebiotic carbohydrates to develop a synbiotic soft soy cheese. It was observed that the addition of 4% (m/v) prebiotics mixture (galacto-oligosaccharide: inulin = 1:3) to soy cheese significantly improved the growth of LA-1.0738, making it no less than 8.2 log colony-forming unit (CFU)/g during the 28-day storage period, but had limited influence on the viability of S. thermophilus KLDS T1C2 (STT1C2). Meanwhile, because of the presence of prebiotics, soy cheese fermented by LA-1.0738 in co-culture with STT1C2 exhibited higher values of acidity, proteolysis and lipolysis index as well as better texture properties and sensory acceptance. These results suggested that the selected combination of prebiotics could be used as functional ingredients to manufacture soy cheese to maintain the survival of desired LA-1.0738, which contributed to improve the texture and sensory features of soy cheese.

The intrinsic defects in perovskite film can serve as non-radiative recombination center to limit the performance and stability of metal halide perovskite solar cells (PSCs). The additive engineering in perovskite film is always applied to produce high-efficiency PSCs in recent years. Here, a typical donor-acceptor (D-A) structured aggregation-induced emission (AIE) molecule tetraphenylethene-2-dicyano-methylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (TPE-TCF) was introduced into perovskite film. The D-A structure of TPE-TCF molecule provided additional charge transfer channels, contributing to transporting electron of TPE-TCF-based device. The cyano (C≡N) of TPE-TCF can interact with the uncoordinated Pb to from a relatively stable intermediate, PbI

The flexible transparent electrode is a crucial component of wearable photoelectric devices, and has a significant influence on the performance and development of wearable devices. Here, a phosphor/polyimide/polyurethane@silver composite nanofiber (NF) web electrode was fabricated by electrospinning and magnetron sputtering for wearable photoelectric devices. The electrode demonstrated a promising light management ability with converting ultraviolet light to visible light, high conductivity with sheet resistance of 22.1 Ω/square, and high transparency with transmittance of over 80%. Besides, the electrode possessed an excellent stretched capacity with tensile strain of over 100%, and tensile stability with the resistance increased by ∼75% after 500 stretching cycles at the tensile stain of 50%. As a result, a flexible perovskite solar cell (PSC) was assembled by using the NF web electrode, and possessed the power conversion efficiency of 3.47%, which is higher than that of PSCs based on electrodes without phosphor. Furthermore, the flexible PSCs exhibited promising mechanical stability under bending, and could serve as wearable devices. This work provides a feasible and promising method to prepare lightweight, stretchable, light management, and transparent electrodes for photoelectric devices, and may facilitate the development of wearable photoelectric devices.

Perovskite films can be prepared using sec-butyl alcohol (2-BA) by a one-step antisolvent assisted method. However, 2-BA dissolves a necessary perovskite precursor, methylammonium iodide, CH3NH3I, (MAI), which is lost during the fabrication, leaving behind residues of another perovskite precursor, PbI2. The resulting perovskite films show reduced power conversion efficiency (PCE) and poor stability to ambient conditions. In this work, we propose an elegant strategy, i.e., the introduction of a small amount of MAI dissolved in the antisolvent 2-BA (1 mg mL−1). The additional MAI can react with the residual PbI2 during the fabrication to form the desired organic–inorganic hybrid perovskite material, CH3NH3PbI3. The high-quality of the perovskite films obtained can provide larger grain sizes and smoother surfaces, with an ideal PCE of 19.29% and superior moisture stabilities.

Inorganic p-type semiconductors have broadly served as hole transport materials (HTLs) in perovskite solar cells (PSCs) in recent years. Among them, NiCo2O4 with its excellent conductivity and hole mobility is the emerging candidate for HTLs and is attracting increasing attention. Here, we employ a simple hydrothermal method to fabricate high-quality mesoporous NiCo2O4 films as HTLs of PSCs. The study finds that the morphology of NiCo2O4 can be regulated from nanosheets (NSs) to nanowires (NWs) as the hydrothermal reaction time increases, and the morphology of NiCo2O4 significantly affects the device performance. Specially, the device with NWs achieves a best efficiency of 11.58%, ascribed to the fact that such a one dimension material could provide a straight path for hole extraction/transport. And benefiting from the mesoporous structures of NiCo2O4 films, all the devices exhibited a very repeatable and desirable long-term stability. Overall, this work develops alternative NiCo2O4 nanostructure-based HTLs and opens up new opportunities in fabricating PSCs.

To significantly increase the applicability of inverted-planar flexible perovskite solar cells (PSCs), the achievement of high electrical conductivity, excellent moisture resistance and reproducibility of a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hole transport layer with simple fabrication (low cost and ease of mass manufacture) during spin-coating is the goal pursued by researchers. Herein, for the first time, we propose a facile strategy of cryo-controlled quasi-congealing spin-coating to improve the PEDOT:PSS quality to a new extent. The congealed surface and strengthened hydrogen-bonds between solvent and PSS chains can effectively suppress the moisture corrosion during spin-coating. In addition, the electrical conductivity of PEDOT:PSS can be further enhanced owing to the uniformity of PEDOT:PSS grains and a greater co-solvent effect facilitated by induced Young's modulus during spin-coating. A considerably smooth and uniform film with improved conductivity can be achieved even when fabricated in a high humidity environment. Furthermore, this smooth and passivated PEDOT:PSS can facilitate highly crystalline perovskite and better interfacial contact between them, which not only enhances the efficiency, but also greatly improves repeated mechanical deformation stability of PSCs. As a result, the power conversion efficiency (PCE) of rigid and flexible PSCs can be improved to 17.65% and 15.13%, respectively. Both devices show about 14% enhancement in PCE compared to the conventional one.

One-dimensional (1D) TiO2 nanofibrous film with good morphology and electrical characteristics was prepared by electrospinning technique. And then perovskite solar cells (PSCs) were fabricated based on 2-μm-thick mesoporous TiO2 nanofibrous film under ambient conditions even with a high humidity condition more than 40%. The devices show high power conversion efficiency (PCE) due to high porosity that is beneficial to the loading of CH3NH3PbI3 perovskite layer. This high-porosity 1D TiO2 nanofibrous film also acts as a protection layer which can enhance the moisture stability of CH3NH3PbI3. As a result, conversion efficiency of 11.6% and short-circuit current density (Jsc) of 17.3 mA were achieved under 100 mW cm−2 AM 1.5 G solar illumination. These two values are both higher than those of zero-dimensional (0D) TiO2 nanoparticulate film-based devices.

Highly flexible ZrO2/C nanofibers (NFs) coated with Ag nanoparticles (NPs) have been fabricated by a combination of electrospinning, carbonization and hydrothermal treatment. The obtained Ag@ZrO2/C NFs serve as low-cost counter electrodes (CEs) for flexible dye-sensitized solar cells (FDSSCs). A considerable power conversion efficiency of 4.77% is achieved, which is 27.9% higher than the η of ZrO2/C NFs CEs (3.73%) and reaches about 90% of that of Pt CE (5.26%). It can be ascribed to the fact that the introduction of Ag NPs provides a large number of accessible reaction sites for electrolyte ions to rapidly participate in the I3−/I− reaction. Moreover, the Ag NPs can produce synergistic effect with ZrO2/C NFs to further enhance transport capacity and electro-catalytic activity of the Ag@ZrO2/C film. Therefore, the considerable performance together with characteristics of simple preparation, low cost and flexibility suggests the Ag@ZrO2/C film can be promising candidate for the future generation of FDSSC.