You will be shown an abstract from a materials science research paper. Your task is to extract all synthesis operations described in the abstract into a structured JSON format. Your output should be a JSON array. Each entry in the array should be a JSON object describing a single synthesis operation. This object should have the following fields:

- "trigger": A verbal predicate indicating a synthesis operation. This should be a string extracted directly from the abstract.
- "arguments": An array of arguments specifying aspects of the synthesis operation. Each entry in the array should be a length-2 array formatted as [<argument_text>, <argument_type>]. The `argument_text` should be a string extracted directly from the abstract. The `argument_type` should be one of the following types: ["Recipe_Precursor", "Atmospheric_Material", "Participant_Material", "Recipe_Target", "Solvent_Material"].

For instance, suppose an excerpt from the abstract reads:

Tetraethoxysilane (TEOS, 98%) and cetyltrimethylammonium bromide (CTAB, 98%) were purchased from Fluka. The MTTZ-siloxy derivative (triethoxysilyl-propyl-5-mercapto-1-methyl-tetrazole) was synthesized as previously described [38].

This excerpt includes two operations, which could be annotated as follows.

[{"arguments": [["Tetraethoxysilane", "Recipe_Precursor"], ["cetyltrimethylammonium bromide", "Recipe_Precursor"]], "trigger": "purchased"}, {"arguments": [["MTTZ-siloxy derivative", "Recipe_Target"]], "trigger": "synthesized"}]

In your response, please include the JSON and no other text.

Abstract:
10.1039/c5ta01668a
Hysteresis-free and highly stable perovskite solar cells produced via a chlorine-mediated interdiffusion method
All chemicals were purchased from commercial suppliers and used as received unless stated otherwise. PbI2 (Sigma Aldrich, 99%) and methyl ammonium iodide (MAI) (Wako Chem., 98%) were dissolved in anhydrous N,N-dimethylformamide (Wako chem., 99.5%) (400 mg ml-1) and anhydrous 2-propanol (Wako chem.) (50 mg ml-1), respectively. For chlorine doping, 5-20 wt% MACl (Wako chem.) was mixed with the MAI solution. PC61BM (Solenne or Lumitec, 99%) solution (2 wt%) dissolved in anhydrous chlorobenzene (Wako chem., 99%) was used for coating of the electron selective layer. All the solutions were filtered using 0.45 μm syringe filters to avoid the risk of particle formation. UV-curable resins (NagaseChemtex XNR5516Z) were used to seal devices with cavity glasses. The X-ray diffraction patterns of MAPbI3 and MAPbI3-xClx were collected using Bruker D8 advanced X-ray diffractometer (CuKα radiation, λ = 1.54050 Å). The top surface and cross-sectional images were taken by a high resolution scanning electron microscope at 5 kV accelerating voltage (Hitachi-4800). Additionally, elemental mapping was done using energy dispersive X-ray measurement mode at accelerating voltage of 10 kV. The current density-voltage (J-V) characteristics under 1 sun with an AM 1.5G spectral filter (100 mW cm-2, calibrated with a Si reference cell, emission spectrum in Fig. S9+) and incident monochromatic photon to current conversion efficiency (IPCE) spectra or External quantum efficiency (EQE) were measured with a CEP-200BX spectrometer (Bunkokeiki, Tokyo, Japan) at room temperature. To investigate the hysteresis behaviour scan rates were varied from 0.02 to 0.3 V s-1. Histogram of over 240 devices were generated from the devices using 0.18 cm2 aperture mask.
[{"arguments": [["chemicals", "Participant_Material"]], "trigger": "purchased"}, {"arguments": [["anhydrous 2-propanol", "Solvent_Material"], ["methyl ammonium iodide", "Recipe_Precursor"], ["PbI2", "Recipe_Precursor"], ["anhydrous N,N-dimethylformamide", "Solvent_Material"]], "trigger": "dissolved"}, {"arguments": [["MACl", "Recipe_Precursor"], ["MAI", "Participant_Material"]], "trigger": "mixed"}, {"arguments": [["anhydrous chlorobenzene", "Solvent_Material"], ["PC61BM", "Recipe_Precursor"]], "trigger": "dissolved"}, {"arguments": [["solutions", "Participant_Material"]], "trigger": "filtered"}, {"arguments": [["particle", "Participant_Material"]], "trigger": "avoid"}]