Synthetic Control on Structure/Dimensionality and Photophysical Properties of Low Dimensional Organic Lead Bromide Perovskite Muhammed P. U. Haris, ∥,† Rangarajan Bakthavatsalam, ∥,† Samir Shaikh, † Bhushan P. Kore, ‡ Dhanashree Moghe, § Rajesh G. Gonnade, † D. D. Sarma, ‡ Dinesh Kabra, § and Janardan Kundu* ,† † Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune, Dr. Homi Bhabha Road, Pashan Pune, Maharashtra-411008, India ‡ Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, CV Raman Rd, Bengaluru, Karnataka-560012, India § Department of Physics, Indian Institute of Technology Bombay, Main Gate Road, Powai, Mumbai, Maharashtra-400076, India * S Supporting Information ABSTRACT: Low dimensional lead halide perovskites have attracted huge research interest due to their structural diversity and remarkable photophysical properties. The ability to controllably change dimensionality/structure of perovskites remains highly challenging. Here, we report synthetic control on structure/ dimensionality of ethylenediammonium (ED) lead bromide perov- skite from a two dimensionally networked (2DN) sheet to a one dimensionally networked (1DN) chain structure. Intercalation of solvent molecules into the perovskite plays a crucial role in directing the final dimensionality/structure. This change in dimensionality reflects strongly in the observed differences in photophysical properties. Upon UV excitation, the 1DN structure emits white light due to easily formed “self-trapped” excitons. 2DN perovskites show band edge blue emission (∼410 nm). Interestingly, Mn 2+ incorporated 2DN perovskites show a highly red-shif ted Mn 2+ emission peak at ∼670 nm. Such a long wavelength Mn 2+ emission peak is unprecedented in the perovskite family. This report highlights the synthetic ability to control the dimensionality/structure of perovskite and consequently its photophysical properties. ■ INTRODUCTION Organic−inorganic hybrid metal halide perovskites continue to be a fascinating research frontier due to their amazing photophysical properties and myriads of applications. 1−3 Depending upon the connectivity of the constituting metal halide octahedra, these perovskites can be classified as three dimensionally networked (3DN) or two dimensionally networked (2DN) or one dimensionally networked (1DN) or zero dimensionally networked (0DN, isolated octahedra) structures. 4−6 3DN perovskites with the general formula APbX 3 are characterized by corner shared metal halide octahedra with “A” type cation fitting the void created by the interconnected (in three dimensions) network of the octahedra. Recently, 2DN perovskites, which can be thought of as derived from 3DN perovskites by slicing along particular crystal directions, with the general formula of L 2 PbX 4 , have seen a resurgence due to their intriguing fundamental properties and applications. 7 The 2DN perovskites have sheet like layered structures where the corner shared metal halide octahedra are partitioned by the long organic ligand (L) layer. Depending upon the direction of the slicing, the 2DN perovskites could be further classified as flat (001) or corrugated (110) inorganic sheet structures. 8 The structure and photophysical properties of these perovskites with different dimensionalities are widely different. (001) 2DN perovskite shows narrow and blue emission at room temper- ature when excited with near UV light. In comparison, few (110) perovskites with corrugated sheet structure show dramatically different emission profile with very broad emission covering the entire visible spectrum. 9 Such materials emit white light under near UV illumination and are potential candidates for single phase phosphors for solid state lighting applications. It is noteworthy that the observed broad emission in these corrugated systems arises due to self-trapped excitons (light induced transient “excited defect states”). 9 The whole family of organic−inorganic metal halide perovskites (3DN, 2DN, 1DN, 0DN) has metal halide octahedra and organic ligands that are central to the chemistry of the system. Manipulating the metal halides, organic ions, and their reaction chemistry are the crucial handles that act as powerful synthetic tools to create new systems with different band structures and photophysical properties. 10 Control on the degree of confine- ment (dimensionality) in the perovskite based system is likely Received: July 20, 2018 Article pubs.acs.org/IC Cite This: Inorg. Chem. XXXX, XXX, XXX-XXX © XXXX American Chemical Society A DOI: 10.1021/acs.inorgchem.8b02042 Inorg. Chem. XXXX, XXX, XXX−XXX Downloaded via UNIV OF SUNDERLAND on October 19, 2018 at 00:32:34 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.