Maximum quantity allowed is 999
Since the first report published by Miyasaka et al. in 2009,1) the development of perovskite solar cells (PSCs) have been progressed remarkably and the power conversion efficiency (PCE) of the solar cells has reached over 25%.2) Leading research institutes and industries that promote solar cell research try to upscaling and modularization of practical PSCs. However, currently many challenges still remain in commercializing PSCs, especially the hole-transporting layer as the bottlenecks. The widely used hole-transporting materials (HTMs), Spiro-OMeTAD and PTAA, are too expensive for the production of low cost PSCs. Also, some additives have to be used to enhance conductivity. However such additives may decrease device stability.
TCI has developed new HTMs TOP-HTM-α1 [B5672] and TOP-HTM-α2 [T3722]. Unlike Spiro-OMeTAD, PSCs based on TOP-HTM-α1 and TOP-HTM-α2 exhibit significant PCEs both with and without additives. These HTMs are useful for stable PSCs and are available at reasonable prices.3)
Advantages
- Realize a high PCE both with or without additives
- Realize a highly stable perovskite solar cell with low cost
Device Fabrication Process
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Preparation of HTM solution
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1. With additives
HTMs are dissolved in chlorobenzene at concentration of 40 mg/mL with additives.
- TOP-HTM-α1
The amount of LiTFSI and TBP are 4.8 mg and 15.2 µL for 1 mL of HTM solution.
HTM solution is heated at 70 °C. - TOP-HTM-α2
The amount of LiTFSI and TBP are 6.0 mg and 19.0 µL for 1 mL of HTM solution.
HTM solution is heated at 85 ˚C.
2. Without additives
HTMs are dissolved in 1,1,2,2-tetrachloroethane at concentration of 40 mg/mL.
HTM solution is heated at 70 ˚C. - TOP-HTM-α1
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Fabrication of devices
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- In a glove box filled with N2 gas, hole transport layers are deposited on the perovskite layer by
spin-coating (slope 5 s, 4000 rpm 30 s, slope 5 s). - The resulting film is dried on a hot plate at 70 ˚C for 30 min.
- A metal electrode (Au, etc.) is thermally deposited on the hole transport layer.
- The solar cell devices are stored in air with ~20% relative humidity to promote oxygen doping.
- In a glove box filled with N2 gas, hole transport layers are deposited on the perovskite layer by
Reference
- 1) Organometal halide perovskites as visible-light sensitizers for photovoltaic cells
- 2) NREL solar cell efficiency chart
- 3) Additive-free, Cost-Effective Hole-Transporting Materials for Perovskite Solar Cells Based on Vinyl Triarylamines