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Product Code M2425A1-500mg
Price $213 ex. VAT

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Self-Assembled Monolayer with Carbazole-based Phosphonic Acid

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


2PACz, also known as (2-(9H-carbazol-9-yl)ethyl)phosphonic acid, consists of an electron rich carbazole body with an ethyl phosphonic acid anchoring group.

This material acts as a self-assembled monolayer (SAM) onto indium-tin-oxide (ITO) substrates in organic solar cells and perovskite solar cells. It replaces PEDOT:PSS as hole transport or extracting layer material. In between the ITO substrate and the active layer materials, 2PACz changes the work function of ITO while altering the morphology of the active layer materials.

In perovskite solar cells, 2PACz exhibits a well-suited energetic alignment and a significantly reduced non-radiative recombination at the contact/perovskite interface, outperforming those based on benchmark hole transport layer materials. This self-assembled monolayer has a better band alignment to the valence band of the perovskite absorber, compared to commonly used HTL PTAA.

The use of 2PACz has enabled almost lossless contacts, minimum interfacial recombination, and improved power conversion efficiency in single-junction and tandem solar cells. 2PACz causes spontaneous vertical phase separation of photoreactive layers, forming a vertical component distribution to improve carrier yield-mobility, and suppress the trap-assisted recombination and leaking current in indoor OPVs.

General Information

CAS Number 20999-38-6
Chemical Formula C14H14NO3P
Molecular Weight 275.24 g/mol
Absorption* λmax 340 nm (on ITO glass)
Fluorescence λem (n.a.)
HOMO/LUMO n.a.
Synonyms (2-(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% (1H NMR)
Melting Point Tm = 231 ° C
Appearance Off-white powder/crystals

Chemical Structure

2pacz - 20999-38-6 - (2-(9H-carbazol-9-yl)ethyl)phosphonic acid chemical structure
2PACz - (2-(9H-carbazol-9-yl)ethyl)phosphonic acid chemical structure, 20999-38-6


MSDS Documentation

2pacz - 20999-38-6 - (2-(9H-carbazol-9-yl)ethyl)phosphonic acid2PACz MSDS Sheet

Literature and Reviews

  1. Self-Assembled Monolayer Enables Hole Transport Layer-Free Organic Solar Cells with 18% Efficiency and Improved Operational Stability, Y. Lin et al., ACS Energy Lett. , 5 (9), 2935–2944 (2020); DOI: 10.1021/acsenergylett.0c01421.
  2. Record indoor performance of organic photovoltaics with long-term stability enabled by self-assembled monolayer-based interface management, T. Kim et al., Nano Energy, 112, 108429 (2023); DOI: 10.1016/j.nanoen.2023.108429.
  3. Evaporated Self-Assembled Monolayer Hole Transport Layers: Lossless Interfaces in p-i-n Perovskite Solar Cells, A. Farag et al., Adv. Energy Mater., 13 (8), 2203982 (2023); DOI: 10.1002/aenm.202203982.
  4. Fully Textured, Production-Line Compatible Monolithic Perovskite/Silicon Tandem Solar Cells Approaching 29% Efficiency, L. Mao et al., Adv. Mater., 34 (40), 2206193 (2022); DOI: 10.1002/adma.202206193.
  5. Monolithic All-Perovskite Tandem Solar Cells with Minimized Optical and Energetic Losses, K. Datta et al., Adv. Mater., 34 (11), 2110053 (2022); DOI: 10.1002/adma.202110053.
  6. Non-Fused Ring Acceptors Achieving over 15.6% Efficiency Organic Solar Cell by Long Exciton Diffusion Length of Alloy-Like Phase and Vertical Phase Separation Induced by Hole Transport Layer, D. Luo et al., Adv. Energy Mater., 13 (6), 2203402 (2023); DOI: 10.1002/aenm.202203402.

To the best of our knowledge the information provided here is accurate. The values provided are typical at the time of manufacture and may vary over time and from batch to batch. Products may have minor cosmetic differences (e.g. to the branding) compared to the photos on our website. All products are for laboratory and research and development use only.

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