4PACz

CAS Number 20999-36-4

Charge Transport Layer Materials, Materials, OLED Materials, Perovskite Interface Materials, Perovskite Materials, Self-Assembled Monolayers (SAMs), Semiconducting Molecules

MSDS

Small Self-Assembled Monolayer Molecule for High Efficiency Solar Cells

4PACz, Hole transport or extraction layer for NFA-polymer solar cells and p-i-n perovskite solar cells

4PACz ((4-(9H-carbazol-9-yl)butyl)phosphonic acid, CAS No. 20999-36-4) is a self-assembly monolayer (SAM) hole transport material. It has a carbazole terminal that can be in direct contact with active layer materials and a phosphonic acid anchor that can be chemically attached to an electrode surface. It also has a n-butyl chain spacer that connects the terminal and anchor. 4PACz has a longer spacer than 2PACz which allows for more stabilizing van der Waals interactions.

When deposited as a monolayer on an electrode, PACzs exhibit lower resistance, higher optical transmittance. Thus it delivers a higher short-circuit current density and fill factor than the most frequently used hole transport layer PEDOT:PSS. The work functions of 2PACz, 3PACz, and 4PACz are 4.94 eV, 4.97 eV, and 4.81 eV respectively, and are slightly lower than that of PEDOT:PSS on ITO, 5.1 eV.

Serving as hole selective contact for organic solar cells and perovskite solar cells, 4PACz 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: 0.30 - 1.0 mg/ml ( 1 mM - 1 mg/ml)
Typical processing procedure: 4PACz is dissolved in IPA at a concentration of 1.0 mM. and stirred for 30 min at 80 °C before deposition. 40 uL of the SAM solution is dropped onto the substrate and spin-coated at 3000 rpm for 30 s. Then after being annealed at 100 ℃ for 15 min, the coated substrate is washed with IPA (60 uL) through spin-coating at 3000 rpm for 30 s, annealed at 100 ℃ for another 5 min (DOI: 10.1002/anie.202213560).

General Information

CAS Number	20999-36-4
Chemical Formula	C₁₆H₁₈NO₃P
Molecular Weight	303.29 g/mol
Absorption*	λ_max (n.a.)
Fluorescence	λ_em (n.a.)
HOMO/LUMO	HOMO = 5.52 eV, LUMO = 2.08 eV
Synonyms	(4-(9H-carbazol-9-yl)butyl)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	Td = 331 °C (Thermogravimetric analysis)
Appearance	White powder

Chemical Structure

4pacz - 20999-36-4 - (4-(9H-carbazol-9-yl)butyl)phosphonic acid — 4pacz - (4-(9H-carbazol-9-yl)butyl)phosphonic acid chemical structure, CAS 20999-36-4.

MSDS Documentation

4PACz MSDS Sheet

Literature and Reviews

π-Expanded Carbazoles as Hole-Selective Self-Assembled Monolayers for High-Performance Perovskite Solar Cells, W. Jiang et al., Angew. Chem. Int. Ed., 134 (51), e202213560 (2022); DOI: 10.1002/ange.202213560.
Finetuning Hole-Extracting Monolayers for Efficient Organic Solar Cells, H. Bin et al., ACS Appl. Mater. Interfaces, 14 (14), 16497–16504 (2022); DOI: 10.1021/acsami.2c01900.
Monolithic perovskite/silicon tandem solar cell with >29% efficiency by enhanced hole extraction, A. Al-Ashouri et al., Science, 370 (6522), 1300-1309 (2020); DOI: 10.1126/science.abd4016.

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