Mesoporous Perovskite Research Articles

Effect of Ionic Liquid Methylammonium Acetate on the Performance of Hole-Transport Material-Free Mesoporous Perovskite Solar Cells with Carbon Electrode

Effect of Ionic Liquid Methylammonium Acetate on the Performance of Hole-Transport Material-Free Mesoporous Perovskite Solar Cells with Carbon Electrode

A Modular Co-assembly Strategy for Ordered Mesoporous Perovskite Oxides with Abundant Surface Active Sites.

The ordered mesoporous perovskite oxides with well-defined mesostrcture and versatile metal sites are attractive, but their successful synthesis faces challenges of complicated assembly dynamics and pore collapse in crystalline calcination. Here, we propose an energy balance concept to reveal interplay relationship in assembly process and realize regulation of porous structure for mesoporous perovskite oxides. A series of ordered mesoporous perovskite oxides with unique porous structure were prepared by a modular co-assembly method. Mesoporous La2 Zr2 O7 shows 94 % conversion and 99 % selectivity for hydrogenation of 5-hydroxymethylfurfural (HMF) to 2,5-bis(hydroxymethyl)furan. Experiments reveal that rich Lewis acid sites, active Zr species, and favorable porous structure promote interaction between mesoporous La2 Zr2 O7 and HMF and reduce catalytic energy barrier. This work provides the insight into molecule co-assembly and developing multiple component ordered mesoporous materials.

A Modular Co‐assembly Strategy for Ordered Mesoporous Perovskite Oxides with Abundant Surface Active Sites

AbstractThe ordered mesoporous perovskite oxides with well‐defined mesostrcture and versatile metal sites are attractive, but their successful synthesis faces challenges of complicated assembly dynamics and pore collapse in crystalline calcination. Here, we propose an energy balance concept to reveal interplay relationship in assembly process and realize regulation of porous structure for mesoporous perovskite oxides. A series of ordered mesoporous perovskite oxides with unique porous structure were prepared by a modular co‐assembly method. Mesoporous La2Zr2O7 shows 94 % conversion and 99 % selectivity for hydrogenation of 5‐hydroxymethylfurfural (HMF) to 2,5‐bis(hydroxymethyl)furan. Experiments reveal that rich Lewis acid sites, active Zr species, and favorable porous structure promote interaction between mesoporous La2Zr2O7 and HMF and reduce catalytic energy barrier. This work provides the insight into molecule co‐assembly and developing multiple component ordered mesoporous materials.

The Influence of the Precursor's Nature and Drying Conditions on the Structure, Morphology, and Thermal Properties of TiO2 Aerogels.

A cost-effective solution for the synthesis of high-porosity TiO2 aerogels, which can be used as a mesoporous perovskite network charge-carrier material during the manufacture of solar cells, is described. The effects of the synthesis parameters (precursor (titanium (IV) isopropoxide (TIP) and tetrabutyl orthotitanate (TBOT)), additional solvent exchange (n-hexane (nH), cyclohexane (CH), and diethyl ether (DE)), subcritical drying (800 mbar vacuum, 70 °C, 8 h), aging, and calcination on the aerogel’s structure have been investigated. Methods of XRD, FT-IR, BET, Raman, STA, SEM, UV–vis, and thermal conductivity measurements were applied to find out the relation between the synthesis conditions and the properties of the synthesized aerogels. Amorphous aerogels are polydispersed systems with the highest probability of pore diameter from 0.5 to 15 nm. An nH-exchanged, aged aerogel synthesized from the precursor TIP shows the highest diameter of pores. After calcination, the aerogels tend to crystallize into an anatase phase and the size of the crystallites depends on the precursor’s nature. Calcination leads to a significant increase in both the apparent and true density of the aerogels, and it also results in an increase in porosity and thermal conductivity.

Optical Modelling of Planar and Fibre Perovskite Solar Cells

We present the optical modelling of a mesoporous fibre perovskite solar cell (PSC). It was conducted by means of the transmission line method (TLM), which was used to calculate the efficiency and short-circuit photo-current density of the cell. The TLM was first applied for a planar mesoporous PSC and verified with the experimental results from the literature. Numerical calculations for both planar and fibre PSC were conducted and analysed regarding their efficiency in terms of optical simulation. The importance of choosing the thin-film layers’ materials and thickness was demonstrated, and a potential improvement using anti-reflection coatings was also examined.

Photoelectric Properties of Planar and Mesoporous Structured Perovskite Solar Cells.

The high efficiency of perovskite solar cells strongly depends on the quality of perovskite films and carrier extraction layers. Here, we present the results of an investigation of the photoelectric properties of solar cells based on perovskite films grown on compact and mesoporous titanium dioxide layers. Kinetics of charge carrier transport and their extraction in triple-cation perovskite solar cells were studied by using transient photovoltage and time-resolved photoluminescence decay measurements. X-ray diffraction analysis revealed that the crystallinity of the perovskite films grown on mesoporous titanium dioxide is better compared to the films grown on compact TiO2. Mesoporous structured perovskite solar cells are found to have higher power conversion efficiency mainly due to enlarged perovskite/mesoporous -TiO2 interfacial area and better crystallinity of their perovskite films.

Scalable Screen-Printed TiO2 Compact Layers for Fully Printable Carbon-Based Perovskite Solar Cells

Fully printable carbon-based perovskite solar cells (C-PSCs) represent some of the most promising perovskite solar cell (PSC) architectures. Highly scalable, stable, and low in cost—these devices consist of a TiO2 compact layer (C-TiO2) and three sequentially screen-printed mesoporous layers of TiO2, ZrO2, and carbon, through which perovskite is infiltrated. While there has been remarkable progress in optimizing and scaling up deposition of mesoporous layers and perovskite, few publications have focused on optimizing C-TiO2. In this work, we investigate the potential for substituting commonly used spray pyrolysis with more easily scaled screen-printing. It was found that when comparing layers of similar thickness, 1 cm2 devices fabricated with printed C-TiO2 exhibited similar power conversion efficiency (PCE) to those fabricated with spray pyrolysis. In contrast, thicker-printed C-TiO2 led to lower efficiency. The influence of TiCl4 treatment on the quality of produced compact layers was also examined. This proved beneficial, mostly in the printed films, where a champion PCE of 13.11% was attained using screen-printed, TiCl4 treated C-TiO2. This work proves that screen-printing is a viable replacement for spray pyrolysis in C-PSCs fabrication.

Preparation of Novel Mesoporous LaFeO3-SBA-15-CTA Support for Syngas Formation of Dry Reforming.

A nanocomposite NiPt/5LSBA-160 catalyst comprised of highly dispersed Ni nanoparticles contacting intimately with Pt over novel mesoporous LaFeO3-SBA-15-CTA support with a high specific surface area (SSA) was successfully developed for the dry reforming of methane. Results revealed that the high SSA mesoporous LaFeO3-SBA-15-CTA materials could first be synthesized by an in situ growth hydrothermal process and used as an excellent carrier candidate of Ni-based catalysts to achieve enhanced catalytic activity due to the strong interaction between LaFeO3 and Ni species. Moreover, the introduction of Pt over a Ni/5LSBA-160 catalyst would further promote the interaction between Ni and support, improve the dispersion of active Ni centers and obtain a higher syngas formation rate as well as tolerance to carbon coking than that of a Pt-free Ni/5LSBA-160 catalyst sample. This finding uncovers a promising prospect for high SSA mesoporous perovskite preparation and utilization in catalysis such as oxidation, hydrogenation, photocatalysis, energy conversion and so on.

Will the Internet of Things Be Perovskite Powered? Energy Yield Measurement and Real-World Performance of Perovskite Solar Cells in Ambient Light Conditions

The number of interconnected devices, often referred to as the Internet of Things (IoT), is increasing at a considerable rate. It is inevitable therefore that so too will the energy demand. IoT describes a range of technologies such as sensors, software, smart meters, wearable devices, and communication beacons for the purpose of connecting and exchanging data with other devices and systems over the internet. Often not located near a mains supply power source, these devices may be reliant on primary battery cells. To avoid the need to periodically replace these batteries, it makes sense to integrate the technologies with a photovoltaic (PV) cell to harvest ambient light, so that the technologies can be said to be self-powered. Perovskite solar cells have proven extremely efficient in low-light conditions but in the absence of ambient and low-light testing standards, or even a consensus on what is defined by “ambient light”, it is difficult to estimate the energy yield of a given PV technology in a given scenario. Ambient light harvesting is complex, subject to spectral considerations, and whether the light source is directly incident on the PV cell. Here, we present a realistic scenario-driven method for measuring the energy yield for a given PV technology in various situations in which an IoT device may be found. Furthermore, we show that laboratory-built p-i-n perovskite devices, for many scenarios, produce energy yields close to that of commercial GaAs solar cells. Finally, we demonstrate an IoT device, powered by a mesoporous carbon perovskite solar module and supercapacitor, and operating through several day–night cycles.

Mesoporous Lani1-Xmnxo3 Perovskite with Enhanced Coke Resistance and Catalytic Performance Synthesized Via Glycine-Assisted Spray Pyrolysis for Dry Reforming of Methane

Mesoporous Lani1-Xmnxo3 Perovskite with Enhanced Coke Resistance and Catalytic Performance Synthesized Via Glycine-Assisted Spray Pyrolysis for Dry Reforming of Methane

Beyond hydrophobicity: how F4-TCNQ doping of the hole transport material improves stability of mesoporous triple-cation perovskite solar cells

High uniformity of hydrophobic F4-TCNQ doping in the spiro-OMeTAD layer hinders the dopant migration towards the anode as well as the dopant aggregation, leading to a T80 shelf-lifetime of >1 year.

Mesoporous perovskite titanates via hydrothermal conversion.

We demonstrate the successful hydrothermal conversion of mesoporous TiO2 to mesoporous perovskite SrTiO3. This method allows for control of pore size distribution and can be readily applied for the preparation of other mesoporous titanates such as BaTiO3 and Li2TiO3. Such high-surface perovskites have potential in high-temperature applications due to their thermal stability.

Graphene incorporated mesoporous perovskite with excellent conductivity and catalytic activity for low temperature solid oxide fuel cells

In modern times, energy transformation sources with superior efficacy and eco-friendliness have become remarkably attractive in terms of fuel cell technology.

Efficient and stable perovskite solar cells using the tungsten trioxide as an interfacial passivation layer

In this paper, the tungsten trioxide (WO3) was used as an interfacial layer between mesoporous TiO2 and perovskite film to suppress grain boundaries of the hole transport layer-free PSCs. With this treatment approach, perovskite film was fabricated with dense and uniform morphology with suppressed charge recombination. Meanwhile, the untreated PSC suffers from severe recombination process, which let to decline the performance of the fabricated device. The UV–vis absorption spectrum of the perovskite with WO3 treatment showed an improved photoelectric performance compared with that of untreated perovskite. The optimized PSCs with WO3/TiO2 bilayer yield a PCE of 14.7% (0.08 cm2 active area) and have long-term ambient stability (30 days). The overall results confirmed that the WO3-coated TiO2-based electron transport layers (ETL) has a positive effect on the photovoltaic performance of the solid state PSCs.

Cotton soot derived carbon nanoparticles for NiO supported processing temperature tuned ambient perovskite solar cells

The emergence of perovskite solar cells (PSCs) in a "catfish effect" of other conventional photovoltaic technologies with the massive growth of high-power conversion efficiency (PCE) has given a new direction to the entire solar energy field. Replacing traditional metal-based electrodes with carbon-based materials is one of the front-runners among many other investigations in this field due to its cost-effective processability and high stability. Carbon-based perovskite solar cells (c-PSCs) have shown great potential for the development of large scale photovoltaics. First of its kind, here we introduce a facile and cost-effective large scale carbon nanoparticles (CNPs) synthesis from mustard oil assisted cotton combustion for utilization in the mesoporous carbon-based perovskite solar cell (PSC). Also, we instigate two different directions of utilizing the carbon nanoparticles for a composite high temperature processed electrode (HTCN) and a low temperature processed electrode (LTCN) with detailed performance comparison. NiO/CNP composite thin film was used in high temperature processed electrodes, and for low temperature processed electrodes, separate NiO and CNP layers were deposited. The HTCN devices with the cell structure FTO/c-TiO2/m-TiO2/m-ZrO2/high-temperature NiO-CNP composite paste/infiltrated MAPI (CH3NH3PbI3) achieved a maximum PCE of 13.2%. In addition, high temperature based carbon devices had remarkable stability of ~ 1000 h (ambient condition), retaining almost 90% of their initial efficiency. In contrast, LTCN devices with configuration FTO/c-TiO2/m-TiO2/m-ZrO2/NiO/MAPI/low-temperature CNP had a PCE limit of 14.2%, maintaining ~ 72% of the initial PCE after 1000 h. Nevertheless, we believe this promising approach and the comparative study between the two different techniques would be highly suitable and adequate for the upcoming cutting-edge experimentations of PSC.

Mesoporous SrTiO3 perovskite as a heterogeneous catalyst for biodiesel production: Experimental and DFT studies

A pure mesoporous SrTiO3 with a honeycomb pore structure is synthesized by the sol-gel method and applied to catalyze transesterification of palm oil with methanol for the biodiesel production. The catalyst is characterized by XRD, CO2/NH3-TPD, N2 adsorption-desorption, SEM-EDX, Raman and XPS to reveal its catalytic performances. The highest FAME yield of 93.14% is achieved in transesterification with the molar ratio of methanol to oil of 15:1 and catalyst concentration of 6 wt% at 170 C for 3 h. Besides, the catalyst is highly tolerant of FFAs and moisture, where the FAME yields of 83.80% and 86.50% are achieved even with the oleic acid and water addition of 10 wt% and 5 wt%. Meanwhile, the catalyst is found to be an effective catalyst for the simultaneous esterification and transesterification. The molecular simulation results show that the Ti sites are more easily attacked by FFAs and the Sr active sites are thus retained for the adsorption of methanol to catalyze transesterification, which explains the bifunctionality of the catalyst.

Improved morphology, structure and optical properties of CH3NH3PbI3 film via HQ additive in PbI2 precursor solution for efficient and stable mesoporous perovskite solar cells

The hybrid halide perovskite is a promising material among next-generation photovoltaic devices due to its high absorption coefficient, low-cost raw materials, and facile film and device fabrication. However, due to the nature of solution processing and lack of precise control over the crystallization of perovskite thin films, a variety of defects, for example, pinholes and grain boundaries can form as a result of the processing conditions that decrease their efficiency and stability. Further, controlling the surface morphology, grain size, charge recombination and optical properties in the perovskite layer is critical to enhancing the photovoltaic performance and stability of solar cells. Here, we mainly focus on a simple and effective method for crystal growth and defect passivation via additive engineering in CH3NH3PbI3 perovskite films were prepared by a two-step deposition process. For this purpose, we introduce the incorporation of hydroxyquinoline (HQ), as one of the Lewis bases with coordinating capability, into the perovskite precursor solution to control nucleation, crystal growth, and optical properties of prepared perovskite films. The results show that HQ additive has a good strategy to improve the perovskite film for perovskite solar cells (PSCs) applications. As a result, we realized stable and efficient mesoporous PSCs, prepared with 0.3 wt% HQ additive, with excellent reproducibility achieving a champion efficiency of 16.33%, higher than that of the pristine one (12.35%) and the ambient condition stability of devices retain 80% of the initial values after 30 days of storage, which is higher than that of pristine PSCs without HQ additive (25%).

Exploring the growth of MAPbI3 under different preparation methods for mesoporous perovskite solar cells

The control of the perovskite growth morphology plays an extremely critical role in mesoporous perovskite solar cells. In this paper, anatase TiO2 nanoparticles (NPs) with high crystallinity were synthesized by a hydrothermal method, and the thickness of the TiO2 mesoporous film (TiO2-MT) was adjusted with concentration of TiO2-NP slurry by controlling ethanol. The perovskite layers were prepared by the traditional two-step (TTS) method, and the improved two-step (ITS) method was used. It is proved that different preparation processes of the perovskite light-absorbing layers have a certain influence on the photoelectric performance of the cell device, but also, the thickness of the TiO2mesoporous film affects the electron transport efficiency at the TiO2/MAPbI3 interface and the suppression of electron–hole recombination through [Formula: see text]–[Formula: see text] positive and negative scanning, electrochemical impedance spectroscopy (EIS) and dark state [Formula: see text]–[Formula: see text] curve analysis of the device. By optimizing the thickness of the TiO2 mesoporous film, the short-circuit photocurrent density ([Formula: see text] of mesoporous perovskite solar cells (M-PSCs) based on the TiO2 mesoporous electron transporting layer of 400 nm thickness is 23.85 mA/cm2, and the optimal photoelectric conversion efficiency (PCE) is 15.38%.

High efficiency planar perovskite solar cell by surface disorder removal on mesoporous tin oxide

Tin oxide (SnO2) is widely used in perovskite solar cells (PSCs) as an electron transport layer (ETL) material. Ethanol usually serves as a solvent of ETL but no one discussed the possible influences caused by ethanol. In this work, the effects of ethanol were investigated systematically. It is clear that ethanol treatment (EtOH-SnO2) can remove surface disorder of mesoporous SnO2 and thus enhance the conductivity as well. As a result, the champion PCE of 21.62% is obtained in PSC with EtOH-SnO2 ETL, which is higher than that of control device (20.70%) due to improved film quality. Meanwhile, compared with control PSCs, the stability of the perovskite layer deposited on EtOH-SnO2 ETL is gradually improved both for the light and thermal stability. Therefore, we make clear that the ethanol treatment can improve the quality of mesoporous SnO2 and perovskite films for optoelectronic device.

Mesoporous perovskite solar cells with Al- and Zn-based metal-organic frameworks

The improvement of lead halide perovskites solar cells (PSC) by hydrophobic metal-organic frameworks (MOF) is one of the promising tools for modern photovoltaic technology to achieve stable and efficient thin-film devices. To show the MOF applicability for PSC, we incorporate two types of MOF: NH2-MIL-53(Al) and basolite Z1200 in n-i-p mesoporous MAPbI3 based solar cells that can add 2.2% efficiency by increasing main photovoltaic parameters. The simplicity of the proposed MOF’s integration allows to use and adopt this approach to incorporate other frameworks for thin-film perovskite devices.