Search Results (10)

In this work, we demonstrate that an external pressure of 15–30 kPa can significantly improve metal halide perovskite (MHP) film thermal stability. We demonstrate this through the application of weight on top of an MHP film during thermal aging in preserving the perovskite phase and the mobile ion concentration, an effect which we hypothesize reduces the extent to which volatile species can escape from the MHP lattice. This method is shown to be effective for a more scalable approach by only applying the weight to a cover glass during the lamination of an epoxy-based resin, after which the weight is removed. The amount of pressure applied during lamination is shown to correlate with stability in both 1 sun illumination and damp heat testing. Lastly, the performance of MHP photovoltaic devices is improved using pressure during lamination, an effect which is attributed to improved interfacial contact between the MHP and the adjacent charge transport layers and healing of any voids or defects that may exist at the buried interface after processing. As such, there are implications for tuning the amount of pressure that is applied during lamination to enable the durability of MHP solar modules toward manufacturing-scale deployment. Full article

In the dynamic field of photovoltaic technology, the pursuit of efficiency and sustainability has led to continuous novelty, shaping the landscape of solar energy solutions. One of the key elements affecting the efficiency of photovoltaic cells of II^nd and III^rd generation is the presence of transparent conductive oxide (TCO) layers, which are key elements impacting the efficiency and durability of solar panels, especially for DSSC, CdTe, CIGS (copper indium gallium diselenide) or organic, perovskite and quantum dots. TCO with low electrical resistance, high mobility, and high transmittance in the VIS–NIR region is particularly important in DSSC, CIGS, and CdTe solar cells, working as a window and electron transporting layer. This layer must form an ohmic contact with the adjacent layers, typically the buffer layer (such as CdS or ZnS), to ensure efficient charge collection Furthermore it ensures protection against oxidation and moisture, which is especially important when transporting the active cell structure to further process steps such as lamination, which ensures the final seal. Transparent conductive oxide layers, which typically consist of materials such as indium tin oxide (ITO) or alternatives such as fluorine-doped tin oxide (FTO), serve dual purposes in photovoltaic applications. Primarily located as the topmost layer of solar cells, TCOs play a key role in transmitting sunlight while facilitating the efficient collection and transport of generated electrical charges. This complex balance between transparency and conductivity highlights the strategic importance of TCO layers in maximizing the performance and durability of photovoltaic systems. As the global demand for clean energy increases and the photovoltaic industry rapidly develops, understanding the differential contribution of TCO layers becomes particularly important in the context of using PV modules as building-integrated elements (BIPV). The use of transparent or semi-transparent modules allows the use of building glazing, including windows and skylights. In addition, considering the dominant position of the Asian market in the production of cells and modules based on silicon, the European market is intensifying work aimed at finding a competitive PV technology. In this context, thin-film, organic modules may prove competitive. For this purpose, in this work, we focused on the electrical parameters of two different thicknesses of a transparent FTO layer. First, the influence of the FTO layer thickness on the transmittance over a wide range was verified. Next, the chemical composition was determined, and key electrical parameters, including carrier mobility, resistivity, and the Hall coefficient, were determined. Full article

To date, scientific research on perovskite solar cells (PSCs) and modules (PSMs) has been carried out for more than 10 years. What is still missing in the market potential of this technology is a complete description of the materials needed to connect and fabricate PSMs in order to build a perovskite solar panel. Starting from the state-of-the-art perovskite solar modules, the material and design optimization using different substrates and architecture types, and ending in the lamination of the panel, this work focusses on the study of the feasibility of the fabrication of a perovskite solar panel. A complete description of all steps required will be provided in detail. Full article

Lead halide perovskite is a new photovoltaic material with excellent material characteristics, such as high optical absorption coefficient, long carrier transmission length, long carrier lifetime and low defect state density. At present, the steady-state photoelectric conversion efficiency of all-perovskite laminated cells is as high as 28.0%, which has surpassed the highest efficiency of monocrystalline silicon cells (26.7%). In addition to its excellent photovoltaic properties, perovskite is also a type of direct bandgap semiconductor with low cost, solubilization, high fluorescence quantum efficiency and tunable radiation wavelength, which brings hope for the realization of electrically pumped low-cost semiconductor lasers. In recent years, a variety of perovskite lasers have emerged, ranging from the type of resonator, the wavelength and pulse width of the pump source, and the preparation process. However, the current research on perovskite lasers is only about the type of resonator, the type of perovskite and the pump wavelength, but the performance of the laser itself and the practical application of perovskite lasers are still in the initial stages. In this review, we summarize the recent developments and progress of solution-processed perovskite semiconductors lasers. We discuss the merit of solution-processed perovskite semiconductors as lasing gain materials and summarized the characteristics of a variety of perovskite lasers. In addition, in view of the issues of poor stability and high current density required to achieve electrically pumped lasers in perovskite lasers, the development trend of perovskite lasers in the future is prospected. Full article

In this work, the performance of a new ethylene-vinyl acetate-based low temperature encapsulation method, conceived to protect perovskite samples from UV irradiation in ambient conditions, has been analyzed. To this purpose, perovskite samples consisting of a set of MAPbI₃ (CH₃NH₃PbI₃) films and MAPbI₃ with an ETL layer were deposited over glass substrates by spin-coating techniques and encapsulated using the new method. The samples were subjected to an UV lamp or to full solar irradiation in ambient conditions, with a relative humidity of 60–80%. Microscope imaging, spectroscopic ellipsometry and Fourier-transform infrared spectroscopy (FTIR) techniques were applied to analyze the samples. The obtained results indicate UV energy is responsible for the degradation of the perovskite layer. Thus, the cut-UV characteristics of the EVA encapsulate acts as an efficient barrier, allowing the laminated samples to remain stable above 350 h under full solar irradiation compared with non-encapsulated samples. In addition, the FTIR results reveal perovskite degradation caused by UV light. To extend the study to encompass whole PSCs, simulations were carried out using the software SCAPS-1D, where the non-encapsulated devices present a short-circuit current reduction after exposure to UV irradiation, while the encapsulated ones maintained their efficiency. Full article

The industrial exploitation of perovskite solar cell technology is still hampered by the lack of repeatable and high-throughput fabrication processes for large-area modules. The joint efforts of the scientific community allowed to demonstrate high-performing small area solar cells; however, retaining such results over large area modules is not trivial. Indeed, the development of deposition methods over large substrates is required together with additional laser processes for the realization of the monolithically integrated cells and their interconnections. In this work, we develop an efficient perovskite solar module based on 2D material engineered structure by optimizing the laser ablation steps (namely P1, P2, P3) required for shaping the module layout in series connected sub-cells. We investigate the impact of the P2 and P3 laser processes, carried out by employing a UV pulsed laser (pulse width = 10 ns; λ = 355 nm), over the final module performance. In particular, a P2 process for removing 2D material-based cell stack from interconnection area among adjacent cells is optimized. Moreover, the impact of the P3 process used to isolate adjacent sub-cells after gold realization over the module performance once laminated in panel configuration is elucidated. The developed fabrication process ensures high-performance repeatability over a large module number by demonstrating the use of laser processing in industrial production. Full article

Recent developments in sensing technologies have triggered a lot of research interest in exploring novel self-powered, inexpensive, compact and flexible pressure sensors with the potential for structural health monitoring (SHM) applications. Herein, we assessed the performance of an embedded mechanoluminescent (ML) and perovskite pressure sensor that integrates the physical principles of mechanoluminescence and perovskite materials. For a continuous in-situ SHM, it is crucial to evaluate the capabilities of the sensing device when embedded into a composite structure. An experimental study of how the sensor is affected by the embedment process into a glass fiber-reinforced composite has been conducted. A series of devices with and without ML were embedded within a composite laminate, and the signal responses were collected under different conditions. We also demonstrated a successful encapsulation process in order for the device to withstand the composite manufacturing conditions. The results show that the sensor exhibits distinct signals when subjected to different load conditions and can be used for the in-situ SHM of advanced composite structures. Full article

Perovskite solar cells, in which decaphenylcyclopentasilane (DPPS) layers were formed on the surface of a CH₃NH₃PbI₃-based perovskite layer, were developed. The photovoltaic properties were improved by controlling the annealing temperature of the perovskite layer. For perovskite layers annealed at high temperatures in the range of 180–220 °C, the perovskite crystals were densely formed and the surface coverage of the perovskite layer was improved. The DPPS-laminated devices suppressed the formation of PbI₂ crystals, and the stability was improved by the DPPS layer. Furthermore, the conversion efficiencies were improved over extended periods of time. Full article

The role of an atomic-layer thick periodic Y–O array in inducing the epitaxial growth of single-crystal hexagonal YAlO₃ perovskite (H-YAP) films was studied using high-angle annular dark-field and annular bright-field scanning transmission electron microscopy in conjunction with a spherical aberration-corrected probe and in situ reflection high-energy electron diffraction. We observed the Y–O array at the interface of amorphous atomic layer deposition (ALD) sub-nano-laminated (snl) Al₂O₃/Y₂O₃ multilayers and GaAs(111)A, with the first film deposition being three cycles of ALD-Y₂O₃. This thin array was a seed layer for growing the H-YAP from the ALD snl multilayers with 900 °C rapid thermal annealing (RTA). The annealed film only contained H-YAP with an excellent crystallinity and an atomically sharp interface with the substrate. The initial Y–O array became the bottom layer of H-YAP, bonding with Ga, the top layer of GaAs. Using a similar ALD snl multilayer, but with the first film deposition of three ALD-Al₂O₃ cycles, there was no observation of a periodic atomic array at the interface. RTA of the sample to 900 °C resulted in a non-uniform film, mixing amorphous regions and island-like H-YAP domains. The results indicate that the epitaxial H-YAP was induced from the atomic-layer thick periodic Y–O array, rather than from GaAs(111)A. Full article

Pressure and temperature are powerful tools applied to perovskites to achieve recrystallization. Lamination, based on recrystallization of perovskites, avoids the limitations and improves the compatibility of materials and solvents in perovskite device architectures. In this work, we demonstrate tightly compacted perovskite laminates on flexible substrates via hot-pressing and investigate the effect of hot-pressing conditions on the lamination qualities and optical properties of perovskite laminates. The optimized laminates achieved at a temperature of 90 °C and a pressure of 10 MPa could sustain a horizontal pulling pressure of 636 kPa and a vertical pulling pressure of 71 kPa. Perovskite laminates exhibit increased crystallinity and a crystallization orientation preference to the (100) direction. The optical properties of laminated perovskites are almost identical to those of pristine perovskites, and the photoluminescence quantum yield (PLQY) survives the negative impact of thermal degradation. This work demonstrates a promising approach to physically laminating perovskite films, which may accelerate the development of roll-to-roll printed perovskite devices and perovskite tandem architectures in the future. Full article