I301 perovskite ink has been formulated in conjunction with our research partners to obtain the highest possible PCEs. Our I301 perovskite ink is designed for processing inside controlled environments such as a nitrogen-filled glovebox.

Ossila’s I301 contains a formulation of Methylammonium Bromide (MABr), Lead Bromide (PbBr₂), Formamidinium Iodide (FAI), Lead Iodide(PbI₂) and Caesium Iodide (CsI) in DMSO solvent. After undergoing conversion through a combination of solvent quenching and thermal annealing steps, I301 ink can be used to create a (Cs_0.05FA_0.81MA_0.14)Pb(I_0.85Br_0.15)₃ perovskite film. For information on the various application of this mixed-cation perovskite, see our applications section.

The main use of I301 is in the fabrication of solar cells. The process recipe for I301 is optimised for glovebox processing under a nitrogen atmosphere. This ink is designed to be used with the device architecture ITO-coated glass/SnO₂/perovskite/Spiro-OMeTAD/Au. PV devices using this architecture achieved an average / peak power conversion efficiency (PCE) of (16.4% ± 3.9)% / 19.0%. (see our device performance section for more information). The ink specifications can be found below along with complete guides on the processing of perovskite inks for standard architecture. Using our provided I301 recipe, 5 ml of solution is capable of processing up to 100 substrates (800 devices using our 8-pixel substrate design).

I301 Perovskite Specifications

I301 Perovskite Applications

Perovskite Photovoltaics: Multiple cation inks are used to create high efficiency devices, regularly achieving over 20% (see the papers cited below). Double cation inks contain two organic A-cations: methylammonium (CH₃NH₃⁺,MA) and formamidinium (CH₃(NH₂)₂⁺,FA) - for more information on the role of A-cations in perovskite crystals, see our perovskite and perovskite solar cells introduction . Double cation perovskites produce impressive intial PCEs but have thermal and phase instabilities, due to the volatility of MA and the phase instability at room temperature of FA-based perovskites. By adding a small amount of Caesium to the precursor, high efficiency devices of 21.1% can maintain over 80% of their initial efficiency after 250 hours of device ageing. Below are a series of papers studying multiple cation perovskite inks. 

• Analysis of the UV–Ozone‐Treated SnO2 Electron Transporting Layer in Planar Perovskite Solar Cells for High Performance and Reduced Hysteresis. P. F. Mendez et. al. Solar RRL. 3 (2019) DOI: 10.1002/solr.201900191
• An Interface Stabilized Perovskite Solar Cell with High Stabilized Efficiency and Low Voltage Loss. J. J. Yoo et. al. Energy Environ. Sci.12 (2019) 2192-2199 DOI: 10.1038/nature14133

• How To Make Over 20% Efficient Perovskite Solar Cells In Regular (N-I-P) And Inverted (P-I-N) Architectures. M. Saliba et al. Chem. Mater. 30 (2018) 4193–4201 DOI: 10.1021/acs.chemmater.8b00136. 
• Cesium-Containing Triple Cation Perovskite Solar Cells: Improved Stability, Reproducibility And High Efficiency. M. Saliba et al. Energy Environ. Sci. 9 (2016) 1989–1997 DOI: 10.1039/c5ee03874j. 

The formulation of triple cation inks varies amongst the literature. Researchers working with Ossila have optimised the I301 ink to produce a high performance ink with impressive lifetime in solution.

I301 Perovskite Processing Guides

Standard Architecture: ITO-coated glass/SnO₂/perovskite/Spiro-OMeTAD/Au

Below is a condensed summary of our fabrication routine for standard architecture devices using our I301 ink:

1. ITO etching:

• A complete guide to FTO/ITO etching can be found on our FTO product page along with an instructional video

2. Substrate cleaning:

• Rub ITO between (gloved) fingers with DI water containing Hellmanex then rinse with water. This is a very important step in the cleaning process.
• Rinse thoroughly in boiling DI water, sonicate for a few minutes in DI water if you want to be extra cautious.
• Rinse and sonicate ITO for 15 minutes in isopropyl alcohol (IPA)
• Dry ITO using filtered compressed gas
• Place the ITO into the UV Ozone cleaner and clean for 15-20 minutes

3. SnO₂ ETL deposition:

• Create a 4:1 suspension of 15% SnO₂ nanoparticles in DI water
• Statically spin coat 50ul of SnO₂ onto substrate fresh from UV ozone 3000rpm for 30s.
• Using a cotton bud and DI water, wipe away the SnO2 layer where the conductive busbars are to be deposited.
• Anneal for 40 mins at 150°C.

5. Perovskite deposition (in glovebox):

• Transfer the substrates into an inert environment glovebox
• Place substrates inside the spin coater.
• Dispense 35 μl of I301 ink onto the substrate. Spin the substrate at 1000 rpm for 10s. After this initial spin step, increase the speed to 3000 rpm over 28s. 13 seconds into the 3000 rpm spin step, dispense 100μl of ethyl acetate to quench the perovskite and leave to spin for a further 15 s (the quenching should be done using a continuous stream of solvent over ~1 s)
• Place substrate back onto the hotplate at 130°C for 10 minutes.

6. Spiro-OMeTAD deposition (in glovebox):

• Prepare the following solutions:
• Spiro-OMeTAD at a concentration of 85 mg/ml in chlorobenzene
• Li-TFSI at a concentration of 500 mg/ml in acetonitrile
• TBP at a volumetric percentage of 98%.
• FK209 Co (III) TFSI at a concentration of 300 mg/ml in acetonitrile
• Combine 1000 μl Spiro-OMeTAD, 20μl Li-TFSI, 34μl TBP and 11μl of FK209 Co (III) TFSI
• Ensure complete solvation of dopants within solution (e.g. vortex for 5 minute/stir overnight) and filter mixture directly before use.
• Start spinning at 4000 rpm for 30 seconds
• Dynamically dispense 25 µl of the combined solution onto the perovskite to create a thin even layer.

7. Spiro-OMeTAD oxidation and anode deposition:

• Remove devices from the glovebox. The spiro-OMeTAD layer will require further oxidation to achieve optimal device performance; this should be achieved after 12 hours of storage in air
• Using tweezers or a razor, scratch away the perovskite and spiro-OMeTAD layer where the conductive busbars are to be deposited (see multi electrode/busbar masks for information on the location of busbars)
• Using thermal evaporation, deposit an 80 nm layer of gold through a shadow mask to define an active area for your device (we recommend the use of Ossila"s multi electrode/busbar mask for optimal device performance)
• Devices measured immediately after being taken out of the glovebox have a PCE 1% lower on average than devices left in air for 12 hours and can be up to 3% lower in extreme cases.

 For a more in-depth device fabrication process, refer to theabove papers.

I301 Device Performance

Standard Architecture Structure

Below is information on photovoltaic devices fabricated using our standard architecture recipe for I301 inks. All scans were taken under AM1.5 illumination, sweeping the voltage from -0.2 V to 1.2 V then from 1.2 V to -0.2 V at a rate of 0.2 V.s^-1 ; no bias soaking was performed on devices.

To the best of our knowledge, the technical information provided here is accurate. However, Ossila assume no liability for the accuracy of this information. The values provided here are typical at the time of manufacture and may vary over time and from batch to batch.