Small Self-Assembled Monolayer Molecule for High Efficiency Perovskite Solar Cells
Hole transport or extraction layer for p-i-n and large area perovskite solar cells
PTZ-CPA is a multifunctional amphiphilic self-assembled monolayer (SAM) material carrying a cyanovinyl phosphonic acid (CPA) anchor group, a rigid conjugated phenyl linker and a phenothiazine (PTZ) end group. Serving as a hole selective layer, PTZ-CPA forms a superwetting interlayer that not only enables effective deposition of high-quality perovskite thin film, but also facilitate hole transport between the active layer and the anode. PTZ−CPA enhances the crystallinity of the perovskite, i.e. formamidinium lead iodide (FAPbI3) hence effectively passivates the electronic defects of the perovskite active layer. Meanwhile, PTZ−CPA shows a larger molecular dipole moment than the carbazole-based hole-selective material MeO−2PACz with improved energy level alignment with FAPbI3 for greater interfacial hole-collections.
As a result, FAPbI3-based inverted perovskite solar cells (PSCs) with PTZ-CPA hole selective interlayer achieved an unprecedented power conversion efficiency (PCE) of 25.35 % under simulated air mass 1.5 (AM1.5) sunlight. Furthermore, Those PSCs with PTZ−CPA self-assembled monolayer demonstrated long-term stability, retaining over 90 % of its initial efficiency after continuous operation at 40 °C for 2,000 hours.
PTZ-CPA works well for both small and large area devices. Serving as hole selective contact for organic solar cells and perovskite solar cells, PTZ-CPA is an alternative to PEDOT:PSS with superior performance and the convenience of solution deposition at low concentration, i.e. 1 mM.
Solution Processing Procedure
Typical processing solvents: Anhydrous ethanol (methanol, IPA, IPA/DMF, THF are also superior solvents)
Typical concentration: 1 mM (0.406 mg/mL) - 1.0 mg/ml
Typical processing procedure: PTZ-CPA solution (concentration range from 0.5-4.0 mg mL-1 in EtOH) is dropped evenly onto the centre of ITO substrate surface and spin-coated for 30 s at the speed of 3000 rpm, then annealed at 100 ℃ on a hotplate for 10 minutes (DOI: 10.1002/aenm.202103175).
General Information
| CAS Number | n.a. |
|---|---|
| Chemical Formula | C21H15N2O3PS |
| Molecular Weight | 406.39 g/mol |
| Absorption* | λmax 363 nm (in THF) |
| Fluorescence | λem (n.a.) |
| HOMO/LUMO | HOMO = - 5.5 eV, LUMO = - 2.43 eV |
| Synonyms | (E)-(2-(4-(10H-phenothiazin-10-yl)phenyl)-1-cyanovinyl)phosphonic acid |
| Classification or Family | Phenothiazine derivatives, Self-assembly monolayers, Hole transport layer, Hole extraction layer, p-i-n Perovskite solar cells, Organic photovoltaics |
Product Details
| Purity | ≥ 98% (HPLC) |
|---|---|
| Melting Point | TGA: Td = 377 °C (5% weight loss) |
| Appearance | Yellow to light brown powder |
Chemical Structure
MSDS Documentation
PTZ-CPA MSDS SheetLiterature and Reviews
- K. Zhao et al. (2024); peri-Fused polyaromatic molecular contacts for perovskite solar cells, Nature, 632, 301–306; DOI: 10.1038/s41586-024-07712-6.
- X. Sun et al. (2025); In-plane compressive strain stabilized formamidinium-based perovskite, Matter, 8 (2), 101920; DOI: 10.1016/j.matt.2024.11.014.