Me-4PACz

Small Self-Assembled Monolayer Molecule for High Efficiency Solar Cells

Me-4PACz, Hole transport or extraction layer for NFA-polymer solar cells and p-i-n perovskite solar cells, CAS No. 2747959-96-0

Overview | Product Information | Solution Processing Procedure

Me-4PACz ((4-(3,6-Dimethyl-9H-carbazol-9-yl)butyl)phosphonic acid), has been widely used as a self-assembled monolayer (SAM) material in highly efficient inverted perovskite, tandem perovskite/Si and single junction organic solar cells. Me-4PACz has a 3,6-dimethyl-9H-carbazole terminal in close contact with the active layer materials, a butyl chain spacer and a phosphonic acid anchor. It serves as a hole extraction interface between the electrode and the active layer.

3,6-Dimethyl-9H-carbazole terminal is hydrophobic and it has proven difficult to produce a uniform perovskite layer on the SAM interface. This problem could be solved either by the the introduction of a second component 1,6-hexylenediphosphonic acid (6dPA) to the precursor solution, or by adding a conjugated polyelectrolyte such as PFN-Br to the Me-4PACz solution to improve the wettability of the SAM surface. PFN-Br also additionally tunes the work function of the Me-4PACz and the built-in voltage in the solar cells, delivering PCE over 20%.

Adding Me-4PACz to PEDOT:PSS mitigates the trap-assisted nonradiative recombination at the HTL interface. Organic solar cells with the composite interface Me-4PACz/PEDOT:PSS exhibit reduced trap densities and low energy losses compared to devices fabricated with a single-layer HTL. Moreover, the composite HTL interface induces vertical phase separation of active layer, leading to significant improvements of the fill factor (FF) for the OSCs.

Serving as hole selective contact for organic solar cells and perovskite solar cells, Me-4PACz is an alternative to PEDOT:PSS with superior performance with the convenience of solution deposition at low concentration, i.e. 1 mM.

General Information

Product Details

Solution Processing Procedure

Typical processing solvents:  Anhydrous ethanol (methanol, IPA, IPA/DMF, THF are also superior solvents)
Typical concentration: 1 mM (0.33 mg/mL) - 1.0 mg/ml
Typical processing procedure: 40 uL of Me-4PACz solution (0.5 mg in 1 ml ethanol) is deposited onto the centre of the substrate surface and spin-coated for 30 s at the speed of 4000 rpm then annealed at 100 °C for 10 minutes (DOI: 10.1038/s41560-023-01227-6)

Chemical Structure

MSDS Documentation

Me-4PACz MSDS Sheet

Literature and Reviews

1. Co-deposition of hole-selective contact and absorber for improving the processability of perovskite solar cells, X. Zheng et al., Nat Energy 8, 462–472 (2023); DOI: 10.1038/s41560-023-01227-6.
   
2. Resolving the Hydrophobicity of the Me-4PACz Hole Transport Layer for Inverted Perovskite Solar Cells with Efficiency >20%, K. Hossain et al., ACS Energy Lett., 8 (9), 3860–3867 (2023); DOI: 10.1021/acsenergylett.3c01385.
   
3. Wettability Improvement of a Carbazole-Based Hole-Selective Monolayer for Reproducible Perovskite Solar Cells, A. Al-Ashouri et al., ACS Energy Lett., 8(2), 898–900 (2023); DOI: 10.1021/acsenergylett.2c02629.
   
4. Suppressing Trap-Assisted Nonradiative Recombination via Interface Modification for Achieving Efficient Organic Solar Cells, Z. Ge et al., Adv. Energy Mater., 2400203 (2024); DOI: 10.1002/aenm.202400203.
   
5. Enhancing the efficiency and longevity of inverted perovskite solar cells with antimony-doped tin oxides, J. Li et al., Nat Energy 9, 308–315 (2024); DOI: 10.1038/s41560-023-01442-1.
   

Licensed by Helmholtz-Zentrum Berlin für Materialien und Energie GmbH in Germany and Kaunas University of Technology in Lithuania.

Related Products

Self-Assembled Monolayers

Self-Assembled Monolayers (SAMs)

Perovskite Interface Materials

Perovskite Interface Materials

Charge Transport Layer

Charge Transport Layer Materials