Browse
Submit Data
Databases
API
Help

Dataset Information

16 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Reducing Defects in Organic-Lead Halide Perovskite Film by Delayed Thermal Annealing Combined with KI/I₂ for Efficient Perovskite Solar Cells.

ABSTRACT: This study improved quality of CH₃NH₃PbI₃ (MAPbI₃) perovskite films by delaying thermal annealing in the spin coating process and introducing KI and I₂ to prepare MAPbI₃ films that were low in defects for high-efficiency perovskite solar cells. The influences of delayed thermal annealing time after coating the MAPbI₃ perovskite layer on the crystallized perovskite, the morphology control of MAPbI₃ films, and the photoelectric conversion efficiency of solar cells were investigated. The optimal delayed thermal annealing time was found to be 60 min at room temperature. The effect of KI/I₂ additives on the growth of MAPbI₃ films and the corresponding optimal delayed thermal annealing time were further investigated. The addition of KI/I₂ can improve perovskite crystallinity, and the conductivity and carrier mobility of MAPbI₃ films. Under optimized conditions, the photoelectric conversion efficiency of MAPbI₃ perovskite solar cells can reach 19.36% under standard AM1.5G solar illumination of 100 mW/cm².

SUBMITTER: Lee KM

PROVIDER: S-EPMC8234527 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Effects of Annealing Conditions on Mixed Lead Halide Perovskite Solar Cells and Their Thermal Stability Investigation.

Project description:In this work, efficient mixed organic cation and mixed halide (MA0.7FA0.3Pb(I0.9Br0.1)?) perovskite solar cells are demonstrated by optimizing annealing conditions. AFM, XRD and PL measurements show that there is a better perovskite film quality for the annealing condition at 100 °C for 30 min. The corresponding device exhibits an optimized PCE of 16.76% with VOC of 1.02 V, JSC of 21.55 mA/cm² and FF of 76.27%. More importantly, the mixed lead halide perovskite MA0.7FA0.3Pb(I0.9Br0.1)? can significantly increase the thermal stability of perovskite film. After being heated at 80 °C for 24 h, the PCE of the MA0.7FA0.3Pb(I0.9Br0.1)? device still remains at 70.00% of its initial value, which is much better than the control MAPbI? device, where only 46.50% of its initial value could be preserved. We also successfully fabricated high-performance flexible mixed lead halide perovskite solar cells based on PEN substrates.

| S-EPMC5551880 | biostudies-other

Electrically Switchable Amplified Spontaneous Emission from Lead Halide Perovskite Film.

Project description:Electrically tunable optical devices that allow for modulation and detection of the optical signals would be extremely beneficial for the next photonic and electronic technologies. Perovskite materials as an emerging excitonic one provide promising platforms because they offer excitons manipulated by an external electrical field and efficient coupling to light. However, so far, electrically modulated switches based on perovskite amplified spontaneous emission (ASE) still remain unexplored. Here, we prepared perovskite films on indium tin oxide substrates by a spin-coating method and characterized their ASE behaviors. Based on it, we designed and fabricated electrically switchable ASE devices of perovskite film based on a light-emitting diode device configuration. Under the externally applied current, this device exhibits good controllable optoelectronic switching behaviors. Furthermore, this photoelectric response can be modulated by the different current densities. Our strategy for electrically switchable perovskite ASE will promote integrated applications in optoelectronic devices and provide valuable experience for the development of electrically pumped perovskite lasers.

| S-EPMC8675001 | biostudies-literature

Reducing Detrimental Defects for High-Performance Metal Halide Perovskite Solar Cells.

Project description:In several photovoltaic (PV) technologies, the presence of electronic defects within the semiconductor band gap limit the efficiency, reproducibility, as well as lifetime. Metal halide perovskites (MHPs) have drawn great attention because of their excellent photovoltaic properties that can be achieved even without a very strict film-growth control processing. Much has been done theoretically in describing the different point defects in MHPs. Herein, we discuss the experimental challenges in thoroughly characterizing the defects in MHPs such as, experimental assignment of the type of defects, defects densities, and the energy positions within the band gap induced by these defects. The second topic of this Review is passivation strategies. Based on a literature survey, the different types of defects that are important to consider and need to be minimized are examined. A complete fundamental understanding of defect nature in MHPs is needed to further improve their optoelectronic functionalities.

| S-EPMC7187320 | biostudies-literature

Stabilizing Organic-Inorganic Lead Halide Perovskite Solar Cells With Efficiency Beyond 20.

Project description:The power conversion efficiency (PCE) of organic-inorganic lead halide perovskite solar cells (PSCs) has exceeded 25%, approaching the best record of their silicon counterpart. However, lifetime issues still stand between PSCs and the goal of mass commercialization. For instance, most photoactive perovskites are hydrophilic, and moisture can quickly turn some of their constituents to compounds yielding trap states. Some perovskites are not thermally stable in the temperature window of solar cell operation and will transform into photo-inactive non-perovskites. If a perovskite is of an inadequate quality, e.g., vacancies, surface area, or grain boundaries per unit volume are high, there exist more defect sites, acting as migration pathways for perovskite ions under photo-bias, and the migration changes the perovskite's composition. An unstable perovskite/charge transport material (CTM) interface allows cross-contamination between molecules from both sides of the interface. Even without external stress, perovskite ions in an operating PSC undergo redox processes, which create defect states or initiate chemical chain reactions to accelerate PSC degradation. This mini-review discussed recent progress in solving issues, including the above, to stabilize PSCs with competitive PCE beyond 20%. The remarkable longevity of 15 PSCs under accelerated aging tests was probed in depth from three viewpoints: (1) perovskite compositions and dopants, (2) perovskite additives, and (3) CTMs. This mini-review, within which crucial perovskite-stabilizing methods were systematically analyzed, can be used as a quick-start guide when dealing with PSCs' stability in the future.

| S-EPMC7399487 | biostudies-literature

Understanding how excess lead iodide precursor improves halide perovskite solar cell performance.

Project description:The presence of excess lead iodide in halide perovskites has been key for surpassing 20% photon-to-power conversion efficiency. To achieve even higher power conversion efficiencies, it is important to understand the role of remnant lead iodide in these perovskites. To that end, we explored the mechanism facilitating this effect by identifying the impact of excess lead iodide within the perovskite film on charge diffusion length, using electron-beam-induced current measurements, and on film formation properties, from grazing-incidence wide-angle X-ray scattering and high-resolution transmission electron microscopy. Based on our results, we propose that excess lead iodide in the perovskite precursors can reduce the halide vacancy concentration and lead to formation of azimuthal angle-oriented cubic α-perovskite crystals in-between 0° and 90°. We further identify a higher perovskite carrier concentration inside the nanostructured titanium dioxide layer than in the capping layer. These effects are consistent with enhanced lead iodide-rich perovskite solar cell performance and illustrate the role of lead iodide.

| S-EPMC6098034 | biostudies-literature

Benzodithiophene-Based Spacers for Layered and Quasi-Layered Lead Halide Perovskite Solar Cells.

Project description:Incorporating extended pi-conjugated organic cations in layered lead halide perovskites is a recent trend promising to merge the fields of organic semiconductors and lead halide perovskites. Herein, we integrate benzodithiophene (BDT) into Ruddlesden-Popper (RP) layered and quasi-layered lead iodide thin films (with methylammonium, MA) of the form (BDT)2 MAn-1 Pbn I3n+1 . The importance of tuning the ligand chemical structure is shown as an alkyl chain length of at least six carbon atoms is required to form a photoactive RP (n=1) phase. With N=20 or 100, as prepared in the precursor solution following the formula (BDT)2 MAN-1 PbN I3N+1 , the performance and stability of devices surpassed those with phenylethylammonium (PEA). For N=100, the BDT cation gave a power conversion efficiency of up to 14.7 % vs. 13.7 % with PEA. Transient photocurrent, UV photoelectron spectroscopy, and Fourier transform infrared spectroscopy point to improved charge transport in the device active layer and additional electronic states close to the valence band, suggesting the formation of a Lewis adduct between the BDT and surface iodide vacancies.

| S-EPMC8361775 | biostudies-literature

Enhanced performance of tin halide perovskite solar cell by addition of lead thiocyanate.

Project description:Organic-inorganic hybrid halide perovskites have attracted great attention as a new type of photovoltaic materials. However, lead (Pb) perovskite solar cells (PSCs) would cause environmental pollution in future large-scale applications. Therefore, it is imperative to find environmentally-friendly metals to replace lead. Although tin (Sn) halide perovskites can be regarded as a valid alternative to lead perovskites, their poor stability and lower conversion efficiency hinder the substitution of Sn for Pb. In this work, highly uniform and pinhole-free perovskite films were prepared by the introduction of a small amount of lead thiocyanate in precursor solutions. The CH3NH3SnI3 (MASnI3) films with Pb additive show an absorption edge of 950 nm. Besides, lead ions can depress the LUMO energy level of Sn-based perovskite materials, which is a benefit to an increase in the opencircuit voltages of PSCs. Consequently, the enhanced performance was achieved in the PSCs based on MASnI3 with a fill factor of 66%, open circuit voltage of 0.54 V and maximum power conversion efficiency of 6.03%.

| S-EPMC9079876 | biostudies-literature

Lead halide perovskite vortex microlasers.

Project description:Lead halide perovskite microlasers have been very promising for versatile optoelectronic applications. However, most perovskite microlasers are linearly polarized with uniform wavefront. The structured laser beams carrying orbital angular momentum have rarely been studied and the applications of perovskites in next-generation optical communications are thus hindered. Herein, we experimentally demonstrate the perovskite vortex microlasers with highly directional outputs and well-controlled topological charges. High quality gratings have been experimentally fabricated in perovskite film and the subsequent vertical cavity surface emitting lasers (VCSELs) with divergent angles of 3o are achieved. With the control of Archimedean spiral gratings, the wavefront of the perovskite VCSELs has been switched to be helical with topological charges of q = -4 to 4. This research is able to expand the potential applications of perovskite microlasers in hybrid integrated photonic networks, as well as optical computing.

| S-EPMC7519163 | biostudies-literature

Lead Sequestration from Halide Perovskite Solar Cells with a Low-Cost Thiol-Containing Encapsulant.

Project description:Perovskite solar cells (PSCs) are being studied and developed because of the outstanding properties of halide perovskites as photovoltaic materials and high conversion efficiencies achieved with the best PSCs. However, leaching out of lead (Pb) ions into the environment presents potential public health risks. We show that thiol-functionalized nanoparticles provide an economic way of minimizing Pb leaching in the case of PSC module damage and subsequent water exposure (at most, ∼2.5% of today's crystal silicon solar panel production cost per square meter). Using commercial materials and methods, we retain ∼90% of Pb without degrading the photovoltaic performance of the cells, compared with nonencapsulated devices, yielding a worst-case scenario of top-soil pollution below natural Pb levels and well below the U.S. Environmental Protection Agency limits.

| S-EPMC9264311 | biostudies-literature

Formamidinium Lead Halide Perovskite Nanocomposite Scintillators.

Project description:While there is great demand for effective, affordable radiation detectors in various applications, many commonly used scintillators have major drawbacks. Conventional inorganic scintillators have a fixed emission wavelength and require expensive, high-temperature synthesis; plastic scintillators, while fast, inexpensive, and robust, have low atomic numbers, limiting their X-ray stopping power. Formamidinium lead halide perovskite nanocrystals show promise as scintillators due to their high X-ray attenuation coefficient and bright luminescence. Here, we used a room-temperature, solution-growth method to produce mixed-halide FAPbX3 (X = Cl, Br) nanocrystals with emission wavelengths that can be varied between 403 and 531 nm via adjustments to the halide ratio. The substitution of bromine for increasing amounts of chlorine resulted in violet emission with faster lifetimes, while larger proportions of bromine resulted in green emission with increased luminescence intensity. By loading FAPbBr3 nanocrystals into a PVT-based plastic scintillator matrix, we produced 1 mm-thick nanocomposite scintillators, which have brighter luminescence than the PVT-based plastic scintillator alone. While nanocomposites such as these are often opaque due to optical scattering from aggregates of the nanoparticles, we used a surface modification technique to improve transmission through the composites. A composite of FAPbBr3 nanocrystals encapsulated in inert PMMA produced even stronger luminescence, with intensity 3.8× greater than a comparative FAPbBr3/plastic scintillator composite. However, the luminescence decay time of the FAPbBr3/PMMA composite was more than 3× slower than that of the FAPbBr3/plastic scintillator composite. We also demonstrate the potential of these lead halide perovskite nanocomposite scintillators for low-cost X-ray imaging applications.

| S-EPMC9268382 | biostudies-literature