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Product Code M2451A1-500mg
Price $260 ex. VAT

Small Self-Assembled Monolayer Molecule for High Efficiency Solar Cells

Cl-2PACz, Hole transport or extraction layer for NFA-polymer solar cells and p-i-n perovskite solar cells


Cl-2PACz ([2-(3,6-dichloro-9H-carbazol-9-yl)ethyl]phosphonic acid) is a halogenated self-assembled monolayer (SAM) material with a 3,6-dichloro-9H-carbazole terminal group, a phosphonic acid anchor and an ethyl spacer between the hole transporting terminal and the anchor to the surface of the electrode. Cl-2PACz has been proven an effective hole-selective contact to replace PEDOT:PSS on ITO for all organic non-fullerene polymer solar cells.

With strong electron-withdrawing capability and empty 3d orbits, chlorine atom intends to form strong noncovalent interactions, such as Cl···S and Cl···π interactions. The synergistic effect of electronegativity, together with the empty 3d orbits of chlorine atoms, lead to increased intramolecular and intermolecular interactions, resulting better charge mobilities on the interface.

Bulk heterojunction (BHJ) solar cells utilizing PEDOT:PSS free ITO/Cl-2PACz anodes with PM6:PM7-Si as the binary polymer donors, BTP-eC9 as the non-fullerene acceptor demonstrated a maximum PCE of 18.5%. This was a great enhancement from that of PEDOT:PSS coated electrode (17.5%). It was also observed that OPV solar cells with Cl-2PACz as the interlayer showed better device stability under continuous illumination with white light than those with PEDOT:PSS as the hole transport layer. The device performance improvements with the interlayer of Cl-2PACz sandwiched between the anode and the photoactive layer are from a combined result of increased charge mobilities and supressed charge recombination, reduced resistance at the interface and longer carrier lifetime.

Serving as hole selective contact for organic solar cells and perovskite solar cells, Cl-2PACz is an alternative to PEDOT:PSS with superior performance with the convenience of solution deposition at low concentration, i.e. 1 mM.

Solution Processing Procedure


Typical processing solvents: Anhydrous ethanol (IPA, IPA/DMF are also superior solvents)
Typical concentration: 0.3 - 1.0 mg/ml
Typical processing procedure: Cl-2PACz is dissolved in anhydrous ethanol at a concentration of 0.3 mg/ml. The solution is applied directly onto the ITO substrate for 20 s followed by spin-coating the solution for 30 s at 3000 rpm. The resulting Cl-2PACz coated substrate is then cooled to toom temperature after being annealed for 4 min at 50 - 100 ℃, followed by being washed twice with the same Cl-2PACz solution (0.3 mg/mL) (DOI: 10.1002/aenm.202202503).

General Information


CAS Number n.a.
Chemical Formula C14H12NO3P
Molecular Weight 344.13 g/mol
Absorption* λmax = ~360 nm (in ethanol)
Fluorescence λem (n.a.)
HOMO/LUMO HOMO = 6.05 eV, LUMO = 2.67 eV
Synonyms (2-(3,6-Dichloro-9H-carbazol-9-yl)ethyl)phosphonic acid
Classification or Family Carbazole 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 n.a.
Appearance White powder


Chemical Structure


Cl-2PACz - [2-(3,6-dichloro-9H-carbazol-9-yl)ethyl]phosphonic acid
Cl-2PACz - (2-(3,6-Dichloro-9H-carbazol-9-yl)ethyl)phosphonic acid chemical structure.

MSDS Documentation


Cl-2PACz - [2-(3,6-dichloro-9H-carbazol-9-yl)ethyl]phosphonic acidCl-2PACz MSDS Sheet

Literature and Reviews


  1. 18.9% Efficient Organic Solar Cells Based on n-Doped Bulk-Heterojunction and Halogen-Substituted Self-Assembled Monolayers as Hole Extracting Interlayers, Y. Lin et al., Adv. Energy Mater., 12, 220250 (2022); DOI: 10.1002/aenm.202202503.
  2. Self-Assembled Interlayer Enables High-Performance Organic Photovoltaics with Power Conversion Efficiency Exceeding 20%, S. Guan et al., Adv. Mater., 2400342 (2024); DOI: 10.1002/adma.202400342.
  3. A 19% efficient and stable organic photovoltaic device enabled by a guest nonfullerene acceptor with fibril-like morphology, H. Chen et al., Energy Environ. Sci., 16, 1062-1070 (2023); DOI: 10.1039/D2EE03483B.

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

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