HTL201

Self-Assembled Monolayer (SAM) Molecule for High Efficiency Perovskite Solar Cells Hole transport layer for p-i-n perovskite solar cells, hole selection layer (HSL), HTL201, (3-((9-Ethyl-9H-carbazol-3-yl)oxy)propyl)phosphonic acid, CAS No. 3048172-00-2 Overview | Product Information | MSDS | Literature | Related Products | Technical Support HTL210, (3-((9-ethyl-9H-carbazol-3-yl)oxy)propyl)phosphonic acid, is a self-assembled monolayer material designed for high-efficiency inverted perovskite or perovskite/silicon tandem solar cells. HTL210 features an asymmetric molecular structure with an ethylated carbazole terminal, a flexible alkyloxy linker, and a phosphonic acid anchor. With an electron donating carbazole terminal, HTL210 serves as hole selective layer in between the substrate and the perovskite active layer. The novel alkyloxy linker of HTL201 yields minimized steric hindrance and improved coverage on the transparent conductive oxide (TCO) recombination layer, while comparing with other self-assembled monolayers with typically a nitrogen-bonded phosphonic acid group, such as Me-4PACz or MeO-4PACz. With a dipole moment (μ) of 3.48 D, HTL210 shows better coordination interaction with the perovskite film to effectively reduce non-radiative recombination at the buried interface for better charge extraction efficiency. Moreover, the perfect energy-level alignment between HTL201 and the perovskite warrants an impressive voltage of nearly 2 V for perovskite/silicon tandem solar cells, giving a certified power conversion efficiency of up to 34.58% based on a silicon heterojunction solar cell, with JSC of 20.80 mA, and FF of 83.63% for a 1.004 cm2 device. Serving as hole selective contact for organic solar cells and perovskite solar cells, HTL201 is an alternative to PEDOT:PSS with superior performance and the convenience of solution deposition at low concentration, i.e. 1 mM. General Information CAS Number 3048172-00-2 Chemical Formula C17H20NO4P Molecular Weight 333.32 g/mol Absorption* λmax (n.a.) Fluorescence λem (n.a.) HOMO/LUMO HOMO = -5.11 eV Synonyms (3-((9-Ethyl-9H-carbazol-3-yl)oxy)propyl)phosphonic acid Classification or Family Carbazole derivatives, Self-assembly monolayers, Hole transport layer, Hole selection layer, p-i-n Perovskite solar cells, Tandem solar cells Product Details Purity ≥98% (HPLC) Melting Point Td > 250 °C Appearance Off-white to white powder/crystals Solution Processing Procedure Typical processing solvents: Methanol, ethanol. IPA, DMF Typical suggested concentration: 1.0 mg/ml or 1.0 mM Typical processing procedure: HTL201 is dissolved in ethanol at a concentration of 0.5 mg/ml. The solution is then spin-coated onto a clean and ultraviolet-treated ITO or FTO substrate surface for 30 seconds at 3,000 rpm, followed by annealing for 5 min at 100 ℃. Chemical Structure HTL201, (3-((9-Ethyl-9H-carbazol-3-yl)oxy)propyl)phosphonic acid chemical structure MSDS Documentation HTL201 MSDS Sheet Literature and Reviews L. Jia et al. (2025), Efficient perovskite/silicon tandem with asymmetric self-assembly molecule, Nature, 644, 912–919; DOI: 10.1038/s41586-025-09333-z. A. Ullah et al. (2026), Self-Assembled Monolayers in p–i–n Perovskite Solar Cells: Molecular Design, Interfacial Engineering, and Machine Learning–Accelerated Material Discovery, Adv. Mater., e20220; DOI: 10.1002/adma.202520220. Licensed by Helmholtz-Zentrum Berlin für Materialien und Energie GmbH in Germany and Kaunas University of Technology in Lithuania. Related Products [[collection handle="self-assembled-monolayers" limit="5"]] Self-Assembled Monolayers Perovskite Materials Semiconducting Molecules