Browse
Submit Data
Databases
API
Help

Dataset Information

28 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Chemical Vapor Deposited Mixed Metal Halide Perovskite Thin Films.

ABSTRACT: In this article, we used a two-step chemical vapor deposition (CVD) method to synthesize methylammonium lead-tin triiodide perovskite films, MAPb_1-xSn_xI₃, with x varying from 0 to 1. We successfully controlled the concentration of Sn in the perovskite films and used Rutherford backscattering spectroscopy (RBS) to quantify the composition of the precursor films for conversion into perovskite films. According to the RBS results, increasing the SnCl₂ source amount in the reaction chamber translate into an increase in Sn concentration in the films. The crystal structure and the optical properties of perovskite films were examined by X-ray diffraction (XRD) and UV-Vis spectrometry. All the perovskite films depicted similar XRD patterns corresponding to a tetragonal structure with I4cm space group despite the precursor films having different crystal structures. The increasing concentration of Sn in the perovskite films linearly decreased the unit volume from about 988.4 Å³ for MAPbI₃ to about 983.3 Å³ for MAPb₀.₃₉Sn₀.₆₁I₃, which consequently influenced the optical properties of the films manifested by the decrease in energy bandgap (E_g) and an increase in the disorder in the band gap. The SEM micrographs depicted improvements in the grain size (0.3-1 µm) and surface coverage of the perovskite films compared with the precursor films.

SUBMITTER: Magubane SS

PROVIDER: S-EPMC8269519 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Control over Crystal Size in Vapor Deposited Metal-Halide Perovskite Films.

Project description:Understanding and controlling grain growth in metal halide perovskite polycrystalline thin films is an important step in improving the performance of perovskite solar cells. We demonstrate accurate control of crystallite size in CH3NH3PbI3 thin films by regulating substrate temperature during vacuum co-deposition of inorganic (PbI2) and organic (CH3NH3I) precursors. Films co-deposited onto a cold (-2 °C) substrate exhibited large, micrometer-sized crystal grains, while films that formed at room temperature (23 °C) only produced grains of 100 nm extent. We isolated the effects of substrate temperature on crystal growth by developing a new method to control sublimation of the organic precursor, and CH3NH3PbI3 solar cells deposited in this way yielded a power conversion efficiency of up to 18.2%. Furthermore, we found substrate temperature directly affects the adsorption rate of CH3NH3I, thus impacting crystal formation and hence solar cell device performance via changes to the conversion rate of PbI2 to CH3NH3PbI3 and stoichiometry. These findings offer new routes to developing efficient solar cells through reproducible control of crystal morphology and composition.

| S-EPMC7147257 | biostudies-literature

Single-Source Vapor-Deposited Cs2AgBiBr6 Thin Films for Lead-Free Perovskite Solar Cells.

Project description:Lead-free double perovskites have been considered as a potential environmentally friendly photovoltaic material for substituting the hybrid lead halide perovskites due to their high stability and nontoxicity. Here, lead-free double perovskite Cs2AgBiBr6 films are initially fabricated by single-source evaporation deposition under high vacuum condition. X-ray diffraction and scanning electron microscopy characterization show that the high crystallinity, flat, and pinhole-free double perovskite Cs2AgBiBr6 films were obtained after post-annealing at 300 °C for 15 min. By changing the annealing temperature, annealing time, and film thickness, perovskite Cs2AgBiBr6 solar cells with planar heterojunction structure of FTO/TiO2/Cs2AgBiBr6/Spiro-OMeTAD/Ag achieve an encouraging power conversion efficiency of 0.70%. Our preliminary work opens a feasible approach for preparing high-quality double perovskite Cs2AgBiBr6 films wielding considerable potential for photovoltaic application.

| S-EPMC6956276 | biostudies-literature

High-Speed Vapor Transport Deposition of Perovskite Thin Films.

Project description:Intensive research of hybrid metal-halide perovskite materials for use as photoactive materials has resulted in an unmatched increase in the power conversion efficiency of perovskite photovoltaics (PVs) over the last couple of years. Now that lab-fabricated perovskite devices rival the efficiency of silicon PVs, the next challenge of scalable mass manufacturing of large perovskite PV panels remains to be solved. For that purpose, it is still unclear which manufacturing method will provide the lowest processing cost and highest quality solar cells. Vapor deposition has been proven to work well for perovskites as a controllable and repeatable thin-film deposition technique but with processing speeds currently too slow to adequately lower the production costs. Addressing this challenge, in the present work, we demonstrate a high-speed vapor transport processing technique in a custom-built reactor that produces high-quality perovskite films with unprecedented deposition speed exceeding 1 nm/s, over 10× faster than previous vapor deposition demonstrations. We show that the semiconducting perovskite films produced with this method have excellent crystallinity and optoelectronic properties with 10 ns charge carrier lifetime, enabling us to fabricate the first photovoltaic devices made by perovskite vapor transport deposition. Our experiments are guided by computational fluid dynamics simulations that also predict that this technique could lead to deposition rates on the order of micrometers per second. This, in turn, could enable cost-effective scalable manufacturing of the perovskite-based solar technologies.

| S-EPMC6748557 | biostudies-literature

Thickness-Dependent Swelling Behavior of Vapor-Deposited Smart Polymer Thin Films.

Project description:In this contribution, the temperature-dependent swelling behavior of vapor-deposited smart polymer thin films is shown to depend on cross-linking and deposited film thickness. Smart polymers find application in sensor and actuator setups and are mostly fabricated on delicate substrates with complex nanostructures that need to be conformally coated. As initiated chemical vapor deposition (iCVD) meets these specific requirements, the present work concentrates on temperature-dependent swelling behavior of iCVD poly(N-isopropylacrylamide) thin films. The transition between swollen and shrunken state and the corresponding lower critical solution temperature (LCST) was investigated by spectroscopic ellipsometry in water. The films' density in the dry state evaluated from X-ray reflectivity could be successfully correlated to the position of the LCST in water and was found to vary between 1.1 and 1.3 g/cm3 in the thickness range 30-330 nm. This work emphasizes the importance of insights in both the deposition process and mechanisms during swelling of smart polymeric structures.

| S-EPMC6300310 | biostudies-literature

Oxidative chemical vapor deposition of polyaniline thin films.

Project description:Polyaniline (PANI) is synthesized via oxidative chemical vapor deposition (oCVD) using aniline as monomer and antimony pentachloride as oxidant. Microscopy and spectroscopy indicate that oCVD processing conditions influence the PANI film chemistry, oxidation, and doping level. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) indicate that a substrate temperature of 90 °C is needed to minimize the formation of oligomers during polymerization. Lower substrate temperatures, such as 25 °C, lead to a film that mostly includes oligomers. Increasing the oxidant flowrate to nearly match the monomer flowrate favors the deposition of PANI in the emeraldine state, and varying the oxidant flowrate can directly influence the oxidation state of PANI. Changing the reactor pressure from 700 to 35 mTorr does not have a significant effect on the deposited film chemistry, indicating that the oCVD PANI process is not concentration dependent. This work shows that oCVD can be used for depositing PANI and for effectively controlling the chemical state of PANI.

| S-EPMC5480348 | biostudies-literature

High External Photoluminescence Quantum Yield in Tin Halide Perovskite Thin Films.

Project description:We show that pristine thin films made of tin halide perovskite have external photoluminescence quantum yield comparable to that of lead halide perovskite, i.e., the material in use to prepare state-of-the-art perovskite solar cells.

| S-EPMC7887870 | biostudies-literature

Applicability of Vapor-Deposited Thermoresponsive Hydrogel Thin Films in Ultrafast Humidity Sensors/Actuators.

Project description:Thermoresponsive polymers reversibly react to changes in temperature and water content of their environment (i.e., relative humidity, RH). In the present contribution, the thermoresponsiveness of poly(N-vinylcaprolactam) thin films cross-linked by di(ethylene glycol) divinyl ether deposited by initiated chemical vapor deposition are investigated to assess their applicability to sensor and actuator setups. A lower critical solution temperature (LCST) is observed at around 16 °C in aqueous environment, associated with a dramatic change in film thickness (e.g., 200% increase at low temperatures) and refractive index, while only thermal expansion of the polymeric system is found, when ramping the temperature in dry atmosphere. In humid environment, we observed a significant response occurring in low RH (already below 5% RH), with the moisture swelling the thin film (up to 4%), but mainly replacing air in the polymeric structure up to ∼40% RH. Non-temperature-dependent swelling is observed up to 80% RH. Above that, thermoresponsive behavior is also demonstrated to be present in humid environment for the first time, whereas toward 100% RH, film thickness and index appear to approach the values obtained in water at the respective temperatures. The response times are similar in a large range of RH and are faster than the ones of the reference humidity sensor used (i.e., seconds). A sensor/actuator hygromorphic device was built by coating a thin flower-shaped poly(dimethylsiloxane) (PDMS) substrate with the thermoresponsive polymer. The large swelling due to water uptake upon exposure to humid environment at temperatures below the LCST caused the petals to bend, mimicking the capability of plants to respond to environmental stimuli via reversible mechanical motion.

| S-EPMC7076731 | biostudies-literature

Confining metal-halide perovskites in nanoporous thin films.

Project description:Controlling the size and shape of semiconducting nanocrystals advances nanoelectronics and photonics. Quantum-confined, inexpensive, solution-derived metal halide perovskites offer narrowband, color-pure emitters as integral parts of next-generation displays and optoelectronic devices. We use nanoporous silicon and alumina thin films as templates for the growth of perovskite nanocrystallites directly within device-relevant architectures without the use of colloidal stabilization. We find significantly blue-shifted photoluminescence emission by reducing the pore size; normally infrared-emitting materials become visibly red, and green-emitting materials become cyan and blue. Confining perovskite nanocrystals within porous oxide thin films drastically increases photoluminescence stability because the templates auspiciously serve as encapsulation. We quantify the template-induced size of the perovskite crystals in nanoporous silicon with microfocus high-energy x-ray depth profiling in transmission geometry, verifying the growth of perovskite nanocrystals throughout the entire thickness of the nanoporous films. Low-voltage electroluminescent diodes with narrow, blue-shifted emission fabricated from nanocrystalline perovskites grown in embedded nanoporous alumina thin films substantiate our general concept for next-generation photonic devices.

| S-EPMC5544398 | biostudies-other

Electrochemical Hole Injection Selectively Expels Iodide from Mixed Halide Perovskite Films.

Project description:Halide ion mobility in metal halide perovskites remains an intriguing phenomenon, influencing their optical and photovoltaic properties. Selective injection of holes through electrochemical anodic bias has allowed us to probe the effect of hole trapping at iodide (0.9 V) and bromide (1.15 V) in mixed halide perovskite (CH3NH3PbBr1.5I1.5) films. Upon trapping holes at the iodide site, the iodide gradually gets expelled from the mixed halide film (as iodine and/or triiodide ion), leaving behind re-formed CH3NH3PbBr3 domains. The weakening of the Pb-I bond following the hole trapping (oxidation of the iodide site) and its expulsion from the lattice in the form of iodine provided further insight into the photoinduced segregation of halide ions in mixed halide perovskite films. Transient absorption spectroscopy revealed that the iodide expulsion process leaves a defect-rich perovskite lattice behind as charge carrier recombination in the re-formed lattice is greatly accelerated. The selective mobility of iodide species provides insight into the photoinduced phase segregation and its implication in the stable operation of perovskite solar cells.

| S-EPMC6624782 | biostudies-literature

Interlink between Tunable Material Properties and Thermoresponsiveness of Cross-Linked Poly(N-vinylcaprolactam) Thin Films Deposited by Initiated Chemical Vapor Deposition.

Project description:In this contribution, we report on the thin-film synthesis of a novel thermoresponsive polymer, namely, poly(N-vinylcaprolactam) cross-linked by di(ethylene glycol)divinyl ether [p(NVCL-co-DEGDVE)] by initiated chemical vapor deposition (iCVD). Its transition between swollen and shrunken states in film thickness and the corresponding lower critical solution temperature (LCST) was investigated by spectroscopic ellipsometry in water. Water contact angle measurements and nano-indentation experiments reveal that the transition is accompanied by a change in wettability and elastic modulus. The amount of cross-linking was used to tune the thermoresponsive behavior of the thin films, resulting in higher swelling and LCST, increased surface rearrangement, and lower stiffness for less cross-linked polymers. For the first time, the filament temperature during iCVD synthesis was used to vary the chain length of the resulting polymeric systems and, thus, the position of their thermoresponsive transition. With that, swelling of up to 250% compared to the dry thickness and transition temperatures ranging from 16 to 40 °C could be achieved.

| S-EPMC6764023 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data