WEBVTT

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Start by gently rubbing the substrate surface using a gloved hand and Hellmanex to remove contamination.

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Then thoroughly rinse.

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At this stage it is very important to remove all traces of Hellmanex from the substrate.

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After washing the substrate, store in a mixture of deionised water and Hellmanex to avoid strange drying patterns.

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When all the substrates have been rinsed, they should be sonicated in this solution for several minutes.

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Once again, the substrates should be thoroughly rinsed - this time with hot deionised water.

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This is to ensure all of the Hellmanex is removed.

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To further this, the substrates should be dunk-rinsed, if not briefly sonicated in warm dionised water.

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These substrates can then be cleaned in either Acetone or IPA.

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Where extreme uniformity is required, for publication data or large area devices, we recommend cleaning in both Acetone and then IPA.

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Whether using Acetone or IPA, we recommend sonicating for at least 10 minutes.

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Substrates can be cleaned in advance and stored in IPA until required.

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Directly before use, dry with nitrogen gas and place in a UV Ozone Cleaner for at least 15 minutes.

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To make an optimised SNO2 layer, a 3wt% suspension of SNO2 nano particles in distilled water is needed.

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Before use, this solution should be filtered to reduce defects and comets in the film.

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It's beneficial to quickly blow substrates with N2 before spinning each layer.

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Place 50μL of SNO2 on the substrate and spin at 3000 RPM for 30 seconds.

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A cotton swab dipped in deionised water can be used to pattern the substrates.

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A guide explaining how to pattern 8-pixel PV substrates can be found on the Ossila website.

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Once all the SNO2 layers have been swabbed, the substrates can be annealed on a hotplate at approximately 150°C for 30 minutes.

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Placing a beaker over the substrates can help to reduce dust contamination.

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Before you begin the next stage of the fabrication process, place the substrates in the UV Ozone Cleaner for at least 20 minutes.

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To achieve the best efficiencies, I301 perovskite ink should be deposited in an inert environment

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In order to achieve the highest device efficiencies, perovskite layers should be deposited in an inert environment.

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Here, we are using the Ossila Glove Box.

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Filter perovskite material through a 0.2μm filter.

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Place a substrate into the Spin Coater.

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Spead 50 μl of perovskite material onto the substrate

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Spin at 1000 RPM for 10 seconds, then 3000 RPM for 28 seconds.

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At 13 seconds from the end of the cycle, deposit 100μL of antisolvent in one continuous stream.

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There will be a colour change as the intermediate phase forms.

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Once the spin cycle is complete, move the substrate to a hotplate held at 130°C.

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Then anneal for 10 mins at 130°C.

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Take the Spiro-OMeTAD with dopants and filter through a 0.2μm filter.

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Place the perovskite-covered substrate into the Spin Coater and spin at 4000 RPM for 30 seconds.

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During this spin cycle, deposit 25μL of Spiro-OMeTAD dynamically onto the substrate.

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The best Spiro-OMeTAD should be uniform in colour and largely pinhole-free.

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After spinning the Spiro-OMeTAD layers, take the substrates out of the Glove Box.

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It's beneficial to waft over the substrates to remove any surrounding solvent vapours.

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These devices should be kept in a dry place away from UV light overnight.

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This will ensure the Spiro-OMeTAD oxidises and vastly improves device performance.

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Before evaporating the metal contact, remove the excess material around the active area with a razor.

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Aim to take off enough perovskite material so that the break lies within the patterned area of the substrate.

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Finally, swab devices with acetonitrile to ensure full removal of perovskite material.

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Place the patterned devices into the appropriate evaporation mask.

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To test the perovskite devices, place one in a test board along with an appropriate aperture mask.

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Performance metrics are found by running current-voltage sweeps of the device under a solar simulator.

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Open the Ossila Solar Cell I-V software. Enter the experiment settings then start the sweep.

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The JV sweep can be observed in real time.

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Once complete, the results can be found on the right hand side.