From Lead Iodide to a Radical Form Lead‐Iodide Superlattice: High Conductance Gain and Broader Band for Photoconductive Response

• Published in: Angewandte Chemie International Edition Vol. 58; no. 9; pp. 2692 - 2695
• Main Authors: Wang, Guan‐E, Xu, Gang, Zhang, Ning‐Ning, Yao, Ming‐Shui, Wang, Ming‐Sheng, Guo, Guo‐Cong
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 25.02.2019
• Edition: International ed. in English
• Subjects: Conductance; Electrical properties; Halides; inorganic–organic hybrids; Iodides; lead halides; Optical properties; radicals; Resistance; semiconductors; Superlattices; inorganic-organic hybrids; lead halides; radicals; semiconductors; superlattices
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.201812554

Superlattice materials offer new opportunities to modify optical and electrical properties of recently emerging 2D materials. The insertion of tetraethylbenzidine (EtDAB) into interlamination of the established 2D PbI2 semiconductor through a mild solution method yielded the first lead iodide superlattice, EtDAB⋅4PbI2 (EtDAB=tetraethylbenzidine), with radical and non‐radical forms. The non‐radical form has a non‐ionic structure that differs from the common ionic structures for inorganic–organic hybrid lead halides. The radical form shows five orders of magnitude greater conductance and broader photoconductive response range (UV/Vis → UV/Vis‐IR), than pure PbI2 and the non‐radical form of the superlattice. Lead the way: The first lead‐iodide superlattice constructed from non‐ionic organic molecules and PbI2 through van der Waals interactions is a new type of inorganic–organic hybrid and has a radical and a non‐radical form. The radical form has an almost five orders of magnitude greater conductivity and broader band photoconductive response than that of the non‐radical form or pure PbI2.