PSS Layer Research Articles

Solution-Processed NiO as a Hole Injection Layer for Stable Quantum Dot Light-Emitting Diodes

In this work, we fabricated quantum dot light-emitting diodes using solution-processed NiO as the hole injection layer to replace the commonly used poly(3,4-ethylenedioxythiophene): poly(styrene-sulfonate) (PEDOT:PSS) layer. We successfully prepared NiO films by spin coating the NiO precursor, then annealing them, and then treating them with UV-ozone under optimized conditions. The best device with the NiO film shows higher current efficiency (25.1 cd/A) than that with the PEDOT:PSS layer (22.3 cd/A). Moreover, the long-term stability of the devices with NiO which is annealed at 500 °C is improved substantially. These results suggest that the NiO layer can be a good alternative for developing stable devices.

Magnetron-sputtered amorphous V2O5 hole injection layer for high performance quantum dot light-emitting diode

We developed radio frequency (RF) magnetron sputtered amorphous vanadium pentoxide (V2O5) film to use in place of typical PEDOT:PSS or solution-processed metal oxide hole injection layer (HIL) in quantum dot light-emitting diodes (QLEDs). The electrical, optical, and chemical properties of the sputtered V2O5 HIL were correlated with the oxygen flow rate at room temperature. At optimized sputtering conditions, the V2O5 film showed a high optical transparency of 91.93% in the visible wavelength region and a work function of 4.73 eV, which is suitable for HIL in QLEDs. We also investigated the performance of QLEDs with sputtered V2O5 HIL as a function of oxygen flow rate. The QLEDs with optimized V2O5 HIL exhibited a maximum luminance of 198,542 cd/m2, a turn-on voltage of 1.7 V, a max external quantum efficiency of about 8.3%, and a current efficiency of 20.3 cd/A, thereby making it comparable to typical PEDOT:PSS HIL-based QLEDs. The successful operation of QLEDs with sputtered V2O5 as HIL demonstrated that it could be used instead of other materials for next-generation large-area QLED displays.

Asymmetric layer‐by‐layer polyelectrolyte nanofiltration membranes with tunable retention

AbstractNanofiltration (NF) membrane processes are attractive to remove multivalent ions. As ion retention in NF membranes is determined by both size and charge exclusion, negatively charged membranes are required to reject negatively charged ions. Layer‐by‐layer assembly of alternating polycation (PC) and polyanion layers on top of a support is a versatile method to produce membranes. Especially the polyelectrolyte (PE) couple polydiallyldimethylammoniumchloride and poly(sodium‐4‐styrenesulfonate) (PDADMAC/PSS) is extensively investigated. This PE couple cannot form highly negatively charged membrane surfaces, due to interdiffusion and charge overcompensation of PDADMAC into the PSS layers, which limits the operational window to tailor membrane properties. We propose the use of asymmetric layer formation and show how combining two charge densities of one PC can produce negatively charged NF membranes. Starting from hollow fiber ultrafiltration supports coated with base layers of PDADMAC/PSS, they are coated with PDADMAC/PSS or poly(acrylamide‐co‐diallyldimethylammoniumchloride), P(AM‐co‐DADMAC)/PSS layers. P(AM‐co‐DADMAC) has a charge density of only 32% compared to 100% for PDADMAC. The particular novel membranes coated with P(AM‐co‐DADMAC) have a highly negatively charged surface and high permeabilities (7–19 L/[m2hbar]), with high retentions for Na2SO4 of up to 95%. These values position the developed membranes in the top range compared to commercial and other layer‐by‐layer membranes.

Fabrication of Robust Capsules by Sequential Assembly of Polyelectrolytes onto Charged Liposomes.

This work presents a simple methodology for coating small unilamellar liposomes bearing different degrees of positive charge with polyelectrolyte multilayers using the sequential layer-by-layer deposition method. The liposomes were made of mixtures of 1,2-dioleyl-sn-glycero-3-phosphocoline and dimethyl dioctadecyl ammonium bromide (DODAB) and coated by alternated layers of the sodium salt of poly(4-styrenesulfonate) (PSS) and poly(allylamine) (PAH) as polyanions and polycations, respectively. The results show that the zeta potential of the liposomes was not very sensitive to the mole fraction of DODAB in the membrane, XD, in the range 0.3 ≤ XD ≤ 0.8. We were able to coat the liposomes with up to four polymer bilayers. The growth of the capsule size was followed by dynamic light scattering, and in some cases, by cryo-transmission electron microscopy, with good agreement between both techniques. The thickness of the layers, measured from the hydrodynamic radius of the coated liposome, depends on the polyelectrolyte used, so that the PSS layers adopt a much more packaged conformation than the PAH layers. An interesting finding is that the PSS amount needed to reach the isoelectric point of the capsules increases linearly with the charge density of the bare liposomes, whereas the amount of PAH does not depend on it. As expected, the preparation of the multilayers has to be done in such a way that when the system is close to the isoelectric point, the capsules do not aggregate. For this, we dropped the polyelectrolyte solution quickly, stirred it fast, and used dilute liposome suspensions. The method is very flexible and not limited to liposomes or polyelectrolyte multilayers; also, coatings containing charged nanoparticles can be easily made. Once the liposomes have been coated, lipids can be easily eliminated, giving rise to polyelectrolyte nanocapsules (polyelectrosomes) with potential applications as drug delivery platforms.

A new organic-inorganic MgZnO/Au/PEDOT:PSS hybrid heterojunction photodetector fabrication

AbatractThis research reports oxygen zinc magnesium (MgZnO)/gold (Au) photodetectors (PD) and organic-inorganic semiconductors MgZnO/Au/poly(3,4-ethylenedioxythio-phene): poly(4-styrenesulfonate) (PEDOT:PSS) PD research. At room temperature, spin-coating and radio frequency (RF) magnetron sputtering were used to deposit PEDOT:PSS layer and MgZnO thin film on the substrate, respectively. The properties of the heterojunction formed on the MgZnO/PEDOT:PSS inorganic/organic contact interface were studied. In order to manufacture ultraviolet (UV) heterojunction PDs, PEDOT:PSS is used as the hole transport layer (HTL), and MgZnO is used as the electron transport layer (ETL). This heterojunction shows excellent ultraviolet light detection capability. Under 40 V bias, the responsivity of MgZnO/Au PD and MgZnO/Au/PEDOT:PSS heterojunction PD are 0.0473 A W−1 and 0.134 A W−1 under ultraviolet irradiation, respectively. The device shows good Schottky contact between metal semiconductor junctions. The excellent UV detector performance is due to the strong UV absorption of PEDOT: PSS.

The Role of Silver Nanoparticles in the Hole Transport Layer in Organic Solar Cells Based on PBDB-T:ITIC

In this work, the fabrication and characterization of organic solar cells under the bulk heterojunction approach in a direct architecture, with gold nanoparticles (Ag-NPs) disseminated into the hole transport layer (HTL) based on PEDOT:PSS is carried out. The active layer is a blend of PBDB-T donor with the non-fullerene electron acceptor ITIC. Ag-NPs dispersed in deionized water are synthesized by laser ablation protocols using a pulsed Nd:YAG laser. Results show an open-circuit voltage (Voc) of 0.84 V, a short circuit current density (Jsc) of 15.5 mA/cm2, a fill factor (FF) of 0.49% and a power conversion efficiency (PCE) of 6.4% when 5% of Ag-NPs are incorporated into the PEDOT:PSS layer; for pristine PEDOT:PSS film, the photovoltaic parameters are Voc of 0.85 V, Jsc of 15.4 mA/cm2, FF of 0.45% and PCE of 5.9%; these results mean an 8.5% of PCE enhancement with the Ag-NPs incorporation. Ag-NPs are introduced into the pristine layer PEDOT:PSS to increase light absorption into the active layer through the localized surface plasmonic resonance effect.

Free-Standing Composite Films Based on Thiol-Ene and PEDOT: PSS Layers for Optoelectronic Applications.

Free-standing composite films were fabricated by combining the plane parallel layers of thiol-ene based on pentaerythritol tetrakis(3-mercaptopropionate)-1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (PETMP-TTT) UV curable polymer and poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) conductive polymer. A systematic analysis was performed with the focus on mechanical performance of the free-standing composite films. The PEDOT:PSS/PETMP-TTT composite exhibited higher values of adhesion force compared to the free-standing PETMP-TTT film due to hydrophilic nature of the PEDOT:PSS layer. The composite was found to be highly transparent in the range of 380–800 nm. The Young’s modulus and tensile strength of PETMP-TTT were found to be 3.6 ± 0.4 GPa and 19 ± 3 MPa, while for PEDOT:PSS/PETMP-TTT to be 3.5 ± 0.3 GPa and 20 ± 3 MPa, respectively. The sheet resistance values of the PEDOT:PSS layer in the composite film were found to be highly stable after a number of bending iterations with slight increase in sheet resistance from 108 to 118 ± 2 Ω/□. The resultant PEDOT:PSS/PETMP-TTT composite can be further used in optoelectronic applications.

Hybrid Inorganic–Organic Inverted Solar Cells With ZnO/ZnMgO Barrier Layer and Effective Organic Active Layer for Low Leakage Current, Enhanced Efficiency, and Reliability

This article reports fabrication and characterization of an Inverted inorganic-organic hybrid solar cell based on ITO/(ZnO/ZnMgO)/ZnONR/PCBM/P3HT:PCBM/PEDOT:PSS/Ca-Al heterostructure. Four different cells were fabricated with and without the presence of both the ZnO/ZnMgO barrier layer and ZnO nanorod (NR) structures. The oxide layers were grown on indium tin oxide (ITO) coated glass substrates through the following approaches: i) ZnO layer by radio frequency (RF) sputtering, ii) ZnMgO layer by pulsed laser deposition technique, and iii) ZnO NR by hydrothermal method. Compared to conventional only ZnO based solar cells, incorporation of ZnO/ZnMgO layer as the barrier layer resulted in low leakage current that enormously improved the cell performance. The binary metal oxide layer offers a chemical barrier that protects the ITO layer and leads to better electron collection. Incorporation of a thick (~300 nm) P3HT:PCBM layer (instead of conventional and thin (~100 nm) P3HT coating) between the ZnO/ZnMgO and PEDOT:PSS layers improves electron collection efficiencies. Improvement in short circuit current density (J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SC</sub> ) was observed from 9.5 to 12.3 mA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . A significant increase in external quantum efficiency was also observed. Both J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SC</sub> and fill factor were found to be improved simultaneously owing to suitable shunt and series resistance attributes. Furthermore, the presence of the thin ZnMgO layer between P3HT:PCBM and dense ZnO layer suppresses the impact of oxygen vacancies, which in turn improves the charge carrier mobility and lowers leakage current. The fabricated cell showed a power conversion efficiency of ~4.95%. Reliability study for 1400 h indicates that the device outperforms the conventional ZnO-based inverted organic solar cells.

Flexible and Transparent Electrodes of Cu2−XSe with Charge Transport via Direct Tunneling Effect

AbstractIn this paper, it is demonstrated that copper selenide (Cu2−XSe) films onto polyester sheets may serve as transparent electrodes in inorganic–organic hybrid light emission devices (IOHLED), as possible replacement to indium tin oxide or fluorine‐doped tin oxide. The Cu2−XSe film synthesized via bath chemical deposition is electrically stable with a sheet resistance of 148 Ω sq−1 and optical bandgap of 2.3 eV. IOHLED are made with poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) as an organic layer for hole transport and poly[2‐metoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV) as electroluminescent semiconductor. The IOHLED emits in the visible range owing to the simultaneous emission from Cu2−XSe and MEH‐PPV layers. The enhanced performance is explained by analyzing the charge transport mechanisms at the inorganic–organic interface, which for Cu2−XSe/PEDOT:PSS changes from Fowler‐Nordheim to direct tunneling regardless of the device temperature (90–370 K). The onset voltage is 75% smaller than in the absence of the PEDOT:PSS layer due to a 27 meV decrease in the potential barrier, and the direct tunneling becomes more relevant to device performance than the sheet resistance of the Cu2−XSe layer. Upon adding transparency, mechanical flexibility, and covering large areas, the ultrathin Cu2−XSe films on polyester substrates permit new designs for electro‐optical devices with inorganic–organic heterojunctions.

A Hybrid Hole Transport Layer for Perovskite-Based Solar Cells

This paper presents the effect of a composite poly(3,4-ethylenedioxythiophene) polystyrene sulfonate PEDOT:PSS and copper-doped nickel oxide (Cu:NiOx) hole transport layer (HTL) on the performance of perovskite solar cells (PSCs). Thin films of Cu:NiOx were spin-coated onto fluorine-doped tin oxide (FTO) glass substrates using a blend of nickel acetate tetrahydrate, 2-methoxyethanol and monoethanolamine (MEA) and copper acetate monohydrate. The prepared solution was stirred at 65 °C for 4 h and spin-coated onto the FTO substrates at 3000 rpm for 30 s in a nitrogen glovebox. The Cu:NiOx/FTO/glass structure was then annealed in air at 400 °C for 30 min. A mixture of PEDOT:PSS and isopropyl alcohol (IPA) (in 1:0.05 wt%) was spun onto the Cu:NiOx/FTO/glass substrate at 4000 rpm for 60 s. The multilayer structure was annealed at 130 °C for 15 min. Subsequently, the perovskite precursor (0.95 M) of methylammonium iodide (MAI) to lead acetate trihydrate (Pb(OAc)2·3H2O) was spin-coated at 4000 rpm for 200 s and thermally annealed at 80 °C for 12 min. The inverted planar perovskite solar cells were then fabricated by the deposition of a photoactive layer (CH3NH3PbI3), [6,6]-phenyl C61-butyric acid methyl ester (PCBM), and a Ag electrode. The mechanical behavior of the device during the fabrication of the Cu:NiOx HTL was modeled with finite element simulations using Abaqus/Complete Abaqus Environment CAE. The results show that incorporating Cu:NiOx into the PSC device improves its density–voltage (J–V) behavior, giving an enhanced photoconversion efficiency (PCE) of ~12.8% from ~9.8% and ~11.5% when PEDOT:PSS-only and Cu:NiOx-only are fabricated, respectively. The short circuit current density Jsc for the 0.1 M Cu:NiOx and 0.2 M Cu:NiOx-based devices increased by 18% and 9%, respectively, due to the increase in the electrical conductivity of the Cu:NiOx which provides room for more charges to be extracted out of the absorber layer. The increases in the PCEs were due to the copper-doped nickel oxide blend with the PEDOT:PSS which enhanced the exciton density and charge transport efficiency leading to higher electrical conductivity. The results indicate that the devices with the copper-doped nickel oxide hole transport layer (HTL) are slower to degrade compared with the PEDOT:PSS-only-based HTL. The finite element analyses show that the Cu:NiOx layer would not extensively deform the device, leading to improved stability and enhanced performance. The implications of the results are discussed for the design of low-temperature solution-processed PSCs with copper-doped nickel oxide composite HTLs.

Thin film organic electrochemical transistors based on hybrid PANI/PEDOT:PSS active layers for enhanced pH sensing

We report on organic electrochemical transistors (OECTs) with active channels made of hybrid inkjet-printed poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and electropolymerized polyaniline (PANI) layers, exhibiting simultaneously improved electrical and pH sensing characteristics. The aniline electropolymerization with an optimum 6-cycles of cyclic voltammetry forms a porous PANI microstructured layer on the PEDOT:PSS film, resulting in high signal linearity and sensitivity of about 100 mV/pH and 20 μA/pH. The electrochemical impedance spectroscopy analysis demonstrates a 9X higher-change of interfacial capacitance when decreasing the pH with the hybrid PANI-PEDOT:PSS layer, in comparison to a bare PEDOT:PSS layer. The simple fabrication process and the high signal amplification pave the way for flexible and higher-performance pH-sensitive OECTs. These scalable devices, combined with ion-selective OECTs, would lead to a novel tool for multi-parametric analysis in different biofluids.

Silver nanowire/PEDOT:PSS hybrid electrode for flexible organic light-emitting diodes

We prepared a hybrid electrode comprosed of a silver nanowires/poly (3,4-ethylenedioxythiophene): poly(styrenesulfonate) (AgNW/PEDOT:PSS) nanocomposite for flexible organic light-emitting diodes (FOLEDs). To increase the conductivity of PEDOT:PSS, diethylene glycol (DEG) was introduced into the PEDOT:PSS solution. The PEDOT:PSS layer shows a higher figure of merits (FoM) when prepared with the optimum amount of 7 vol%-DEG in the coating solution, due to the three-dimensional conducting network formed in the hybrid electrode. The perfluorinated ionomer (PFI) was also introduced into the PEDOT:PSS solution, and the resulting polymer solution was used to prepare a transparent anode on polymeric substrates. The PEDOT:PSS layers with higher contents of PFI exhibited higher work functions of 5.9 eV, due to control of the surface composition. After bending for 600,000 cycles, the hybrid electrode maintained a low R/R 0 value. When the hybrid electrode with PFI-PEDOT:PSS was used as a transparent anode in a flexible OLED device, the FOLED exhibited a 25% higher current efficiency. Therefore, the enhanced performance of the FOLED devices fabricated on PFI-PEDOT:PSS anodes could be applicable to flexible displays.

Effect of deposition methods on the optical and morphological properties of CH3NH3PbBr3 inverted solar cells

Perovskite solar cells have established their place as one of the most exciting solar cell technologies currently under investigation. The efficiency of solar cells based on perovskite has rapidly increased to over 25%, making this the fastest-advancing solar cell technology. The impressive increase in efficiency has led to an enormous surge in interest. One of the effective ways to achieve reproducibly efficiency perovskite is the deposition method. Here CH3NH3PbBr3 light absorber materials was deposited on the PEDOT:PSS layer via one-step and two-step spin coating methods and their photovoltaic performance are compared. Inverted perovskite solar cells with ITO/PEDOT:PSS/CH3NH3PbBr3/PCBM/Al structure have been investigated. The morphological, structural, optical and electrical properties of the deposited perovskite are found to be critical and the higher performance was obtained from two-step deposition process.

Colorful conducting polymers for vivid solar panels

Photovoltaic (PV) panels with vivid colors provide an additional dimension for developing new applications such as aesthetically appealing solar buildings and mobile products. Thus, rendering PV panel colorful at low cost while keeping high power conversion efficiency (PCE) is of great interest to the community. Based on polymer/Si heterojunction test cells, here we report that color rendering can be made by modifying the optical refractive index of the PEDOT:PSS films. The key to achieving the desired refractive index of the PEDOT:PSS layer for a specific color is to select proper doping material. Guided by theoretical modeling analysis, we have developed 1 × 1 cm2 silicon heterojunction solar cells with colors across the entire visible spectrum while simultaneously achieving a competitive PCE of 13.2%. As a solution-based process is used to fabricate the Si heterojunction cells, the method reported here can be readily scaled up using mature industrial tools such as inkjet printers.

Reduced Graphene Oxide Inserted into PEDOT:PSS Layer to Enhance the Electrical Behaviour of Light-Emitting Diodes.

In this study, poly(9-vinylcarbazole) (PVK)-based LEDs doped with reduced graphene oxide (rGO) and cadmium sulphide (CdS) nanocrystals were fabricated by spin-coating. The hybrid LED structure was a layer sequence of glass/indium tin oxide (ITO)/PEDOT:PSS|rGO/PVK/Al. rGO was included in the poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) layer due to its energy bands being close to PEDOT:PSS bands, and the possibility of using water for dispersing both polymer and flakes. Optical properties such as photoluminescence and UV-Vis absorption were not affected by the addition of rGO to the PEDOT:PSS solution. However, PVK-based LEDs with rGO showed increased current density compared to those without rGO in the hole transporting layer. Higher electroluminescence intensities were observed for rGO-enriched LEDs, although the shape of the spectrum was not modified. LEDs including CdS nanocrystals in the poly(9-vinylcarbazole) emissive layer did not show such dependence on the rGO presence. Though the addition of rGO to PEDOT:PSS still produces a slightly higher current density in CdS doped LEDs, this growth is no longer proportional to the rGO load.

Effects of the PENTACENE as doping material on the power conversion efficiency of P3HT:PCBM based ternary organic solar cells

In organic solar cells (OSCs), changing the device geometry and the photophysical properties of the active layer is an effective way to change the power conversion efficiency (PCE). For this purpose, both the buffer layer was coated between the active layer and the metal and the organic material was doped to the active layer to obtain the ternary structure. In this study, for the fabrication of bulk-heterojunction (BHJ) organic solar cell, the PEDOT:PSS layer was coated on chemically cleaned ITO coated glass substrates by the spin coating method. Subsequently, the P3HT:PCBM blend as an active layer was coated on top of PEDOT:PSS in the glove box using the same method. Finally, aluminum (Al) was coated using thermal evaporation and ITO/PEDOT:PSS/P3HT:PCBM/Al organic solar cells structure as reference device were obtained. Then, PENTACENE material with an organic semiconductor property was doped into P3HT:PCBM blend and ITO/PEDOT:PSS/P3HT:PCBM:PENTACENE/Al bulk heterojunction organic solar cell structure was obtained using the same method. In addition, the effects of OSC on PCE were investigated by coating the 2 nm lithium fluoride layer between the Al and the active layer. For devices, dark and light current density-voltage (J-V) measurements were performed under 100 mW/cm2 in the glove box, and device parameters were calculated by the J-V curve. It was observed that the reference device showed photovoltaic properties under light and its PCE was 0.64%. When the experimental findings obtained were examined, both the LiF buffer layer and PENTACENE doping material improved the ternary OSC device performance and increased the PCE from 0.64% to 2.65%, according to the reference device. As a result of the doping, the mobility of the carrier increased with the increase of photon absorption and the presence of the buffer layer increased the carrier injection. Changing device properties can be explained with these results.

Biocompatible, Transparent, and High-Areal-Coverage Kirigami PEDOT:PSS Electrodes for Electrooculography-Derived Human-Machine Interactions.

Electronic skin sensors prepared from biocompatible and biodegradable polymeric materials significantly benefit the research and scientific community, as they can reduce the amount of effort required for e-waste management by deteriorating or dissolving into the environment without pollution. Herein, we report the use of polylactic acid (PLA)-a promising plant-based bioplastic-and highly transparent, conductive, biocompatible, and flexible poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) materials to fabricate kirigami-based stretchable on-skin electrophysiological sensors via a low-cost and rapid laser cutting technique. The sensor stack with PEDOT:PSS and PLA layers exhibited high transparency (>85%) in the wavelength range of 400-700 nm and stay attached conformally to the skin for several hours without adverse effects. The Y-shaped kirigami motifs inspired by the microcracked gold film endowed the sensor with attributes such as high areal coverage (∼85%), breathability (∼40 g m-2 h-1), and multidirectional stretchability. The sensor has been successfully applied to monitor electrophysiological signals and demonstrated with an eye movement-supported communication interface for controlling home electronic appliances.

Co-immobilization of antioxidant enzymes on titania nanosheets for reduction of oxidative stress in colloid systems

Immobilization of single antioxidant enzyme systems was frequently studied in the past, however, there is a lack of reliable reports on the co-immobilization of such enzymes. Here, an antioxidant enzyme cascade involving superoxide dismutase (SOD) and horseradish peroxidase (HRP) was successfully immobilized on titania nanosheets (TNS) by the sequential adsorption method using poly(diallyldimethylammonium chloride) (PDADMAC) and poly(styrene sulfonate) (PSS) polyelectrolyte building blocks. The development of the cascade system was based on a colloid approach, in which the charging and aggregation processes were optimized in each synthetic step. The polyelectrolyte and enzyme multilayers were built up in two different sequences at the particle interface, namely, TNS-PDADMAC-SOD-PSS-HRP and TNS-HRP-PDADMAC-SOD-PSS. The formation of the polyelectrolyte layers led to charge reversal of the carrier and the saturated PDADMAC and PSS layers stabilized the dispersions, in particular, their resistance against salt-induced aggregation was especially excellent. The results of enzymatic assays revealed that the SOD and HRP-like activities of the composites depended on the location of the enzymes in the hybrid material. The obtained compounds showed remarkable antioxidant effect and were able to simultaneously decompose superoxide radical anions and hydrogen peroxide. The cascade systems are of great promise in industrial manufacturing processes during the preparation of high-quality products without any damages by reactive oxygen species.

Balancing crystallization rate in a mixed Sn–Pb perovskite film for efficient and stable perovskite solar cells of more than 20% efficiency

A surface treatment of PEDOT:PSS layer with [PNA]BF4 is employed to realize vertically homogeneous distribution of Sn/Pb-containing perovskite films through balancing its crystallization rate and achieving chemical encapsulation of the acidic PEDOT:PSS substrate.

Charge transfer balancing of planar perovskite solar cell based on a low cost and facile solution-processed CuOx as an efficient hole transporting layer

Planar perovskite solar cells are known for their ease of fabrication and considerable efficiency. Hole transport layer in these cells is however mostly either expensive organic spiro-OMeTAD or hydrophilic PEDOT: PSS polymer which reduces cell lifespan due to its acidic nature. Copper oxide, on the other hand, is a non-toxic inorganic alternative. It can be synthesized through a facile solution-based process, requiring no vacuum system or N2 glovebox, which makes it conveniently adaptable to large-scale production. Inverted planar perovskite solar cells with CuOx as hole transport layer were studied. To balance the charge transfer in the device and avoid the charge accumulation in the bulk and interfaces, CuOx layer was deposited with different thicknesses. As verified by PL tests, quenching of the deposited CuOx layer was comparable to PEDOT: PSS layer which signifies its effectiveness as a hole transport layer. Optimum observed results were for a cell with an efficiency of 6.26%, Voc of 0.71 V, Jsc of 12.87 mA/cm2, and fill factor of 0.69. Consistent with J–V measurements, electrochemical impedance spectroscopy indicated a significant increase in charge transport resistance between hole transport layer and perovskite film as the CuOx film thickness was increased from 55 nm to 75 nm.