Name: low pressure vapor-assisted solution process for tunable band gap pinhole-free methylammonium lead halide perovskite films
Uploaded: 2017-09-08T11:00:00
Description: Watch this Scientific Journal Video about Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films at JoVE.com

Perovskite process development, thin film synthesis, structural and morphological characterization were performed at the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award Number DE-SC0004993. C.M.S.-F. acknowledges financial support from the Swiss National Science Foundation (P2EZP2_155586).

Caution: Please consult all relevant material safety data sheets (MSDS) before use. Several of the chemicals used in these syntheses are acutely toxic, carcinogenic, and toxic to reproduction. Implosion and explosion risks are associated with the use of a Schlenk line. Please make sure to check the integrity of the glass apparatus before performing the procedure. Incorrect use of the Schlenk line in association with a liquid nitrogen cold trap may result in condensation of liquid oxygen (pale blue) that can become explos...

<ol>
	<li>De Wolf, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organometallic+Halide+Perovskites:+Sharp+Optical+Absorption+Edge+and+Its+Relation+to+Photovoltaic+Performance.">Organometallic Halide Perovskites: Sharp Optical Absorption Edge and Its Relation to Photovoltaic Performance.</a> J. Phys. Chem. Lett. 5 (6), 1035-1039 (2014).</li><li>Noh, J. H., Im, S. H., Heo, J. H., Mandal, T. N., Seok, S. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+Management+for+Colorful,+Efficient,+and+Stable+Inorganic-Organic+Hybrid+Nanostructured+Solar+Cells.">Chemical Management for Colorful, Efficient, and Stable Inorganic-Organic Hybrid Nanostructured Solar Cells.</a> Nano Lett. 13 (4), 1764-1769 (2013).</li><li>Stranks, S. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electron-Hole+Diffusion+Lengths+Exceeding+1+Micrometer+in+an+Organometal+Trihalide+Perovskite+Absorber.">Electron-Hole Diffusion Lengths Exceeding 1 Micrometer in an Organometal Trihalide Perovskite Absorber.</a> Science. 342 (6156), 341-344 (2013).</li><li>Oga, H., Saeki, A., Ogomi, Y., Hayase, S., Seki, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+Understanding+of+the+Electronic+and+Energetic+Landscapes+of+Perovskite+Solar+Cells:+High+Local+Charge+Carrier+Mobility,+Reduced+Recombination,+and+Extremely+Shallow+Traps.">Improved Understanding of the Electronic and Energetic Landscapes of Perovskite Solar Cells: High Local Charge Carrier Mobility, Reduced Recombination, and Extremely Shallow Traps.</a> J. Am. Chem. Soc. 136 (39), 13818-13825 (2014).</li><li>Deschler, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+Photoluminescence+Efficiency+and+Optically+Pumped+Lasing+in+Solution-Processed+Mixed+Halide+Perovskite+Semiconductors.">High Photoluminescence Efficiency and Optically Pumped Lasing in Solution-Processed Mixed Halide Perovskite Semiconductors.</a> J. Phys. Chem. Lett. 5 (8), 1421-1426 (2014).</li><li>Sutter-Fella, C. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+Photoluminescence+Quantum+Yield+in+Band+Gap+Tunable+Bromide+Containing+Mixed+Halide+Perovskites.">High Photoluminescence Quantum Yield in Band Gap Tunable Bromide Containing Mixed Halide Perovskites.</a> Nano Lett. 16 (1), 800-806 (2016).</li><li>Chen, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+and+stable+large-area+perovskite+solar+cells+with+inorganic+charge+extraction+layers.">Efficient and stable large-area perovskite solar cells with inorganic charge extraction layers.</a> Science. 350 (6263), 944-948 (2015).</li><li>Bi, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+luminescent+solar+cells+based+on+tailored+mixed-cation+perovskites.">Efficient luminescent solar cells based on tailored mixed-cation perovskites.</a> Sci. Adv. 2 (1), e1501170 (2016).</li><li>Werner, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+Monolithic+Perovskite/Silicon+Tandem+Solar+Cell+with+Cell+Area+&gt;1+cm2.">Efficient Monolithic Perovskite/Silicon Tandem Solar Cell with Cell Area &gt;1 cm2.</a> J. Phys. Chem. Lett. 7 (1), 161-166 (2016).</li><li>Kranz, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-Efficiency+Polycrystalline+Thin+Film+Tandem+Solar+Cells.">High-Efficiency Polycrystalline Thin Film Tandem Solar Cells.</a> J. Phys. Chem. Lett. 6 (14), 2676-2681 (2015).</li><li>Xing, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low-temperature+solution-processed+wavelength-tunable+perovskites+for+lasing.">Low-temperature solution-processed wavelength-tunable perovskites for lasing.</a> Nat. Mater. 13, 476-480 (2014).</li><li>Deschler, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+Photoluminescence+Efficiency+and+Optically+Pumped+Lasing+in+Solution-Processed+Mixed+Halide+Perovskite+Semiconductors.">High Photoluminescence Efficiency and Optically Pumped Lasing in Solution-Processed Mixed Halide Perovskite Semiconductors.</a> J. Phys. Chem. Lett. 5 (8), 1421-1426 (2014).</li><li>Tan, Z. -. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bright+light-emitting+diodes+based+on+organometal+halide+perovskite.">Bright light-emitting diodes based on organometal halide perovskite.</a> Nat. Nanotechnol. 9, 687-692 (2014).</li><li>Stranks, S. D., Snaith, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metal-halide+perovskites+for+photovoltaic+and+light-emitting+devices.">Metal-halide perovskites for photovoltaic and light-emitting devices.</a> Nat. Nanotechnol. 10, 391-402 (2015).</li><li>Saliba, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cesium-containing+triple+cation+perovskite+solar+cells:+improved+stability,+reproducibility+and+high+efficiency.">Cesium-containing triple cation perovskite solar cells: improved stability, reproducibility and high efficiency.</a> Energy Environ. Sci. 9, 1989-1997 (1989).</li><li>Eperon, G. E., Burlakov, V. M., Docampo, P., Goriely, A., Snaith, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphological+Control+for+High+Performance,+Solution-Processed+Planar+Heterojunction+Perovskite+Solar+Cells.">Morphological Control for High Performance, Solution-Processed Planar Heterojunction Perovskite Solar Cells.</a> Adv. Funct. Mater. 24 (1), 151-157 (2014).</li><li>Jeon, N. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solvent+engineering+for+high-performance+inorganic-organic+hybrid+perovskite+solar+cells.">Solvent engineering for high-performance inorganic-organic hybrid perovskite solar cells.</a> Nat. Mater. 13, 897-903 (2014).</li><li>Liu, M., Johnston, M. B., Snaith, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+planar+heterojunction+perovskite+solar+cells+by+vapour+deposition.">Efficient planar heterojunction perovskite solar cells by vapour deposition.</a> Nature. 501, 395-398 (2013).</li><li>Chen, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Planar+Heterojunction+Perovskite+Solar+Cells+via+Vapor-Assisted+Solution+Process.">Planar Heterojunction Perovskite Solar Cells via Vapor-Assisted Solution Process.</a> J. Am. Chem. Soc. 136 (2), 622-625 (2014).</li><li>Li, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+Planar+Heterojunction+Perovskite+Solar+Cells+by+Controlled+Low-Pressure+Vapor+Annealing.">Fabrication of Planar Heterojunction Perovskite Solar Cells by Controlled Low-Pressure Vapor Annealing.</a> J. Phys. Chem. Lett. 6 (3), 493-499 (2015).</li><li>Li, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Defective+TiO2+with+high+photoconductive+gain+for+efficient+and+stable+planar+heterojunction+perovskite+solar+cells.">Defective TiO2 with high photoconductive gain for efficient and stable planar heterojunction perovskite solar cells.</a> Nat. Commun. 7, 12446 (2016).</li><li>Gonzalez-Carrero, S., Galian, R. E., P&#233;rez-Prieto, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maximizing+the+emissive+properties+of+CH3NH3PbBr3+perovskite+nanoparticles.">Maximizing the emissive properties of CH3NH3PbBr3 perovskite nanoparticles.</a> J. Mater. Chem. A. 3, 9187-9193 (2015).</li><li>Zhou, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antisolvent+diffusion-induced+growth,+equilibrium+behaviours+in+aqueous+solution+and+optical+properties+of+CH3NH3PbI3+single+crystals+for+photovoltaic+applications.">Antisolvent diffusion-induced growth, equilibrium behaviours in aqueous solution and optical properties of CH3NH3PbI3 single crystals for photovoltaic applications.</a> RSC Adv. 5, 85344-85349 (2015).</li></ol>

In order to fabricate highly efficient organo-lead planar perovskite heterojunctions, the homogeneity of the active layer is a key requirement. With respect to existing solution2,16,17 and vacuum-based18,19 methodologies, our process is remarkably amenable to composition tunability of the active layer that can be synthesized over the full CH3NH3PbI<...

Hybrid organic-inorganic lead halide perovskites (CH3NH3PbX3, X = I, Br, Cl) are a new class of semiconductors that has emerged rapidly within the last few years. This material class shows excellent semiconductor properties, such as high absorption coefficient1, tunable bandgap2, long charge carrier diffusion length3, high defect tolerance4, and high photoluminescence quantum yield5,6. The unique combination of these characteristics makes lead halide perovskites very attractive for application in optoelectronic devices, such as single junction7,8 and multijunction photovoltaics9,10, lasers11,12, and LEDs13.
CH3NH3PbX3 films can be fabricated by a variety of synthetic methods14, which aim at improving the efficiency of this semiconducting material for energy applications15. However, optimization of photovoltaic devices relies on the quality of the halide perovskite active layer, as well as its interfaces with charge selective contacts (i.e. electron and hole transport layers), which facilitate photocarrier collection in these devices. Specifically, continuous, pinhole-free active layers are necessary to minimize shunt resistance, thereby improving device performance.
Among the most widespread methods for fabricating organo-lead halide perovskite thin films are solution-based and vacuum-based processes. The most common solution process uses equimolar ratios of lead halide and methylammonium halide dissolved in dimethylformamide (DMF), dimethylsulfoxide (DMSO), or &#947;-butyrolactone (GBL), or mixtures of these solvents.2,16,17 Precursor molarity and solvent type, as well as annealing temperature, time and atmosphere, must be precisely controlled to obtain continuous and pinhole-free films.16 For example, to improve surface coverage, a solvent-engineering technique was demonstrated to yield dense and extremely uniform films.17 In this technique, a non-solvent (toluene) is dripped onto the perovskite layer during the spinning of the perovskite solution.17 These approaches are usually well suited for mesoscopic heterojunctions, which employ mesoporous TiO2 as an electron selective contact with increased contact area and reduced carrier transport length.
However, planar heterojunctions, which use selective contacts based on thin (usually TiO2) films, are more desirable because they provide a simple and scalable configuration that can be more easily adopted in solar cell technology. Therefore, the development of organo-lead halide perovskite active layers that show high efficiency and stability under operation for planar heterojunctions may lead to technological advancements in this field. However, one of the main challenges to fabricate planar heterojunctions is still represented by the homogeneity of the active layer. A few attempts, based on vacuum processes, have been made to prepare uniform layers on thin TiO2 films. For example, Snaith and collaborators have demonstrated a dual evaporation process, which yield highly homogenous perovskite layers with high power conversion efficiencies for photovoltaic applications.18 While this work represents a significant advancement in the field, the use of high vacuum systems and the lack of tunability of the composition of the active layer limit the applicability of this method. Interestingly, extremely high uniformity has been achieved with the vapor-assisted solution process (VASP)19 and modified low pressure VASP (LP-VASP)6,20. While the VASP, proposed by Yang and collaborators19, requires higher temperatures and the use of a glove box, the LP-VASP is based on the annealing of a lead halide precursor layer in the presence of methylammonium halide vapor, at reduce pressure and relatively low temperature in a fumehood. These specific conditions enable access mixed perovskite compositions, and fabrication of pure CH3NH3PbI3, CH3NH3PbI3-xClx, CH3NH3PbI3-xBrx, and CH3NH3PbBr3 can be easily achieved. Specifically, CH3NH3PbI3-xBrx films over the full composition space can be synthesized with high optoelectronic quality and reproducibility6,20.
Herein, we provide a detailed description of the protocol for the synthesis of organic-inorganic lead halide perovskite layers via LP-VASP, including the procedure for synthesizing the methylammonium halide precursors. Once the precursors are synthesized, formation of CH3NH3PbX3 films consists of a two-step procedure that comprises i) the spin-coating of the PbI2/PbBr2 (PbI2, or PbI2/PbCl2) precursor on glass substrate or fluorine-doped tin oxide (FTO) coated glass substrate with planar TiO2, as electron transport layer, and ii) the low pressure vapor-assisted annealing in mixtures of CH3NH3I and CH3NH3Br that can be finely adjusted depending on the desired optical bandgap (1.6 eV&#160;&#8804; Eg &#8804; 2.3 eV). Under these conditions, the methylammonium halide molecules present in the vapor phase slowly diffuse into the lead halide thin film yielding continuous, pinhole-free halide perovskite films. This process yields a two-fold volume expansion from the starting lead halide precursor layer to the completed organic-inorganic lead halide perovskite. The standard thickness of the perovskite film is about 400 nm. It is possible to vary this thickness between 100-500 nm by changing the speed of the second spin coating step. The presented technique results in films of high optoelectronic quality, which translates to photovoltaic devices with power conversion efficiencies of up to 19% using a Au/spiro-OMeTAD /CH3NH3PbI3-xBrx/compact TiO2/ FTO/glass solar cell architecture.21

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Lead (II) bromide, 99.999%</td>
			<td>Sigma-Aldrich</td>
			<td>398853</td>
			<td>Acute toxicity, Carcinogenicity</td>
		</tr>
		<tr>
			<td>Lead (II) Iodide, 99.9985%</td>
			<td>Alfa Aesar</td>
			<td>12724</td>
			<td>Acute toxicity, light sensitive</td>
		</tr>
		<tr>
			<td>N, N-Dimethylformamide, &#62; 99.9%</td>
			<td>Sigma-Aldrich</td>
			<td>270547</td>
			<td>Acute toxicity, flamable; store in well ventilated place</td>
		</tr>
		<tr>
			<td>Isopropyl alcohol, 99.5%</td>
			<td>BDH</td>
			<td>BDH1133-4LP</td>
			<td>Flamable</td>
		</tr>
		<tr>
			<td>Methylamine ca. 40% in water</td>
			<td>TCI</td>
			<td>M0137</td>
			<td>Acute toxicity, flamable; Corrosive</td>
		</tr>
		<tr>
			<td>Hydrobromic acid 48 wt. % in H2O, &#8805;99.99%</td>
			<td>Sigma-Aldrich</td>
			<td>339245</td>
			<td>Acute toxicity, Corrosive; air and light sensitive; store in well ventilated place</td>
		</tr>
		<tr>
			<td>Hydroiodic acid 57 wt. % in H2O, distilled, stabilized, 99.95%</td>
			<td>Sigma-Aldrich</td>
			<td>210021</td>
			<td>Corrosive; air and light sensitive; store in well ventilated place 
			Recommended storage temperature 2/8 &#176;C; air and light sensitiv</td>
		</tr>
		<tr>
			<td>Ethyl Ether Anhydrous BHT Stabilized/Certified ACS</td>
			<td>Fisher Chemicals</td>
			<td>E 138-4</td>
			<td>Acute toxicity, flamable</td>
		</tr>
		<tr>
			<td>Ethanol Denatured (Reagent Alcohol), ACS</td>
			<td>BDH</td>
			<td>BDH1156-4LP</td>
			<td>Flamable</td>
		</tr>
		<tr>
			<td>Alconoxdetergent</td>
			<td>Sigma-Aldrich</td>
			<td>242985</td>
			<td>Soap utilized for substrate cleaning</td>
		</tr>
		<tr>
			<td>Milli-QIntegral 3 Water Purification System</td>
			<td>EMD Millipore</td>
			<td>ZRXQ003WW</td>
			<td>Dispenser of ultrapure water</td>
		</tr>
		<tr>
			<td>Fluorine-doped Thin Oxide (FTO) coated glass</td>
			<td>Thin Film Devices</td>
			<td>Custom</td>
			<td>Glass: dimensions 13.8mm x 15.8mm &#177; 0.2mm, thickness 2.3mm &#177; 0.1mm; FTO: dimensions 3000&#197; &#177; 100&#197;, resistivity 7-10 ohms/sq, transmission 82% @ 550nm)</td>
		</tr>
		<tr>
			<td>Glass substrates</td>
			<td>C &#38; A Scientific - Premiere</td>
			<td>9101-E</td>
			<td>Plain. Length: 75 mm, Width: 25 mm, Thickness: 1 mm</td>
		</tr>
		<tr>
			<td>Ultrasonic Cleaner with Digital Timer and Heater</td>
			<td>VWR</td>
			<td>97043-992</td>
			<td>2.8 L (0.7 gal.)24L x 14W x 10D cm (97/16x 51/2x 315/16&#34;)</td>
		</tr>
		<tr>
			<td>Nuclear Magnetic Resonance Advance 500</td>
			<td>Bruker</td>
			<td>Z115311</td>
			<td></td>
		</tr>
		<tr>
			<td>Quanta 250 FEG Scanning Electron Microscope</td>
			<td>FEI</td>
			<td>743202032141</td>
			<td>Equipped with a Bruker Xflash 5030 Energy-dispersive X-ray detector</td>
		</tr>
		<tr>
			<td>SmartLab X-ray diffractometer</td>
			<td>Rigaku</td>
			<td>2080B411</td>
			<td>Using Cu K&#945; radiation at 40 kV and 40 mA</td>
		</tr>
	</tbody>
</table>

low pressure vapor-assisted solution process for tunable band gap pinhole-free methylammonium lead halide perovskite films

Organo-lead halide perovskites have recently attracted great interest for potential applications in thin-film photovoltaics and optoelectronics. Herein, we present a protocol for the fabrication of this material via the low-pressure vapor assisted solution process (LP-VASP) method, which yields ~19% power conversion efficiency in planar heterojunction perovskite solar cells. First, we report the synthesis of methylammonium iodide (CH3NH3I) and methylammonium bromide (CH3NH3Br) from methylamine and the corresponding halide acid (HI or HBr). Then, we describe the fabrication of pinhole-free, continuous methylammonium-lead halide perovskite (CH3NH3PbX3 with X = I, Br, Cl and their mixture) films with the LP-VASP. This process is based on two steps: i) spin-coating of a homogenous layer of lead halide precursor onto a substrate, and ii) conversion of this layer to CH3NH3PbI3-xBrx by exposing the substrate to vapors of a mixture of CH3NH3I and CH3NH3Br at reduced pressure and 120 &#176;C. Through slow diffusion of the methylammonium halide vapor into the lead halide precursor, we achieve slow and controlled growth of a continuous, pinhole-free perovskite film. The LP-VASP allows synthetic access to the full halide composition space in CH3NH3PbI3-xBrx with 0&#160;&#8804; x&#160;&#8804; 3. Depending on the composition of the vapor phase, the bandgap can be tuned between 1.6 eV&#160;&#8804; Eg&#160;&#8804; 2.3 eV. In addition, by varying the composition of the halide precursor and of the vapor phase, we can also obtain CH3NH3PbI3-xClx. Films obtained from the LP-VASP are reproducible, phase pure as confirmed by X-ray diffraction measurements, and show high photoluminescence quantum yield. The process does not require the use of a glovebox.

Proton nuclear magnetic resonance (NMR) spectra were taken after the methylammonium halide synthesis to verify the molecule purity (Figure 1). Scanning electron microscopy (SEM) images were acquired before and after vapor annealing (Figure 2) to characterize the morphology and the homogeneity of both the mixed lead halide precursor and the CH3NH3PbI3-xBrx films. X-ray diffraction (XRD) ...

Watch this Scientific Journal Video about Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films at JoVE.com

Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films

Here, we present a protocol for the synthesis of CH3NH3I and CH3NH3Br precursors and the subsequent formation of pinhole-free, continuous CH3NH3PbI3-xBrx thin films for the application in high efficiency solar cells and other optoelectronic devices.

Organo-lead halide perovskites have recently attracted great interest for potential applications in thin-film photovoltaics and optoelectronics. Herein, ...

Research

JoVE Journal

Chemistry

Towards Biomimicking Wood: Fabricated Free-standing Films of Nanocellulose, Lignin, and a Synthetic Polycation

Woody materials are comprised of plant cell walls that contain a layered secondary cell wall composed of structural polymers of polysaccharides and ...

Atomically Defined Templates for Epitaxial Growth of Complex Oxide Thin Films

Atomically defined substrate surfaces are prerequisite for the epitaxial growth of complex oxide thin films. In this protocol, two approaches to obtain ...

Preparation of Macroporous Epitaxial Quartz Films on Silicon by Chemical Solution Deposition

This work describes the detailed protocol for preparing piezoelectric macroporous epitaxial quartz films on silicon(100) substrates. This is a three-step ...

Low-energy Cathodoluminescence for (Oxy)Nitride Phosphors

Low-energy Cathodoluminescence for OxyNitride Phosphors

Nitride and oxynitride (Sialon) phosphors are good candidates for the ultraviolet and visible emission applications. High performance, good stability and ...

Epitaxial Growth of Perovskite Strontium Titanate on Germanium via Atomic Layer Deposition

Atomic layer deposition (ALD) is a commercially utilized deposition method for electronic materials. ALD growth of thin films offers thickness control and ...

The Synthesis of [Sn10(Si(SiMe3)3)4]2- Using a Metastable Sn(I) Halide Solution Synthesized via a Co-condensation Technique

The Synthesis of [Sn10SiSiMe334]2- Using a Metastable SnI Halide Solution Synthesized via a Co-condensation Technique

The number of well-characterized metalloid tin clusters, synthesized by applying the disproportionation of a metastable Sn(I) halide in the presence of a ...

Capillary Electrophoresis to Monitor Peptide Grafting onto Chitosan Films in Real Time

Free-solution capillary electrophoresis (CE) separates analytes, generally charged compounds in solution through the application of an electric field. ...

Solution-Processed "Silver-Bismuth-Iodine" Ternary Thin Films for Lead-Free Photovoltaic Absorbers

Bismuth-based hybrid perovskites are regarded as promising photo-active semiconductors for environment-friendly and air-stable solar cell applications. ...

Extending the Lifespan of Soluble Lead Flow Batteries with a Sodium Acetate Additive

In this report, we present a method for the construction of a soluble lead flow battery (SLFB) with an extended cycle life. By supplying an adequate ...

Synthesis of Soft Polysiloxane-urea Elastomers for Intraocular Lens Application

This study discusses a synthesis route for soft polysiloxane-based urea (PSU) elastomers for their applications as accommodating intraocular lenses ...