Molecular Engineering for Enhancing the Dielectric and Optoelectronic Properties of Antimony Corroles

• Published in: Small science Vol. 5; no. 6; pp. 2400589 - n/a
• Main Authors: Pain, Tanmoy, Saifuddin, Md, Sahoo, Anshuman, Mahapatra, Biplab, Kar, Subhajit, Chakraborty, Rwiddhi, Senanayak, Satyaprasad P., Kar, Sanjib
• Format: Journal Article
• Language: English
• Published: Germany John Wiley & Sons, Inc 01.06.2025; John Wiley and Sons Inc; Wiley-VCH
• Subjects: antimony corroles; Crystal structure; density functional theory; Efficiency; Fourier transforms; high dielectric constant material; Ligands; organic solar cells; Oxidation; photoresponsivity; Semiconductors; Spectrum analysis; organic solar cells; photoresponsivity; antimony corroles; high dielectric constant material; density functional theory
• ISSN: 2688-4046; 2688-4046
• DOI: 10.1002/smsc.202400589

Herein, the role of molecular engineering on the optoelectronic properties of antimony corroles with two distinct β‐substituents and two different antimony oxidation states is studied. Insertion of a strong electron‐withdrawing SCN group on the bi‐pyrrole unit of the corrole increases the molecular dipole moment. Consequently, the dielectric constant is enhanced by up to threefold, reaching a value of 8 for antimony(V) tetra(thiocyano)corrole, significantly higher than any solution‐processable organic semiconductor reported to date. Moreover, this SCN‐substituted molecule also exhibits an increased charge carrier mobility by at least two orders of magnitude. A combination of suitable metallic oxidation state and SCN substitution is crucial in defining absorption, charge carrier mobility, and dielectric constant, all of which impact photovoltaic performance. The fluorescence quantum yield of the champion molecule increases by 300%, and the charge carrier lifetime is extended by twofold, indicating fewer nonradiative recombination pathways or a lower degree of disorder. Consequently, single‐component photodetectors with white light responsivity as high as 10 A W−1, ranking among the best in single‐component donor‐based organic semiconductors, and a single‐component solar cell fabricated from antimony(V) tetra(thiocyano)corrole that exhibits an open‐circuit voltage of 0.7 V, at least three times higher than single‐component poly(3‐hexylthiophene) (P3HT)‐based photovoltaic devices, are demonstrated. Molecular engineering of antimony corroles with various β‐substituents and the ability to modulate the oxidation state of the metal ion is employed to demonstrate exceptional optoelectronic properties. The antimony(V) corrole with SCN substituents shows enhanced charge carrier mobility, a high dielectric constant, and a broad absorption range, resulting in superior photoresponse and open‐circuit voltage compared to conventional molecular semiconductors.