Temperature-responsive emission and elastic properties of a new 2D lead halide perovskite†
Abstract
Two-dimensional (2D) organometallic halide perovskites (OHPs) are promising optoelectronic materials because of their excellent stability and tunable band gaps. Herein, we report the optical and elastic properties of a newly synthesized 2D lead halide perovskite, (C9H14ON)2PbI4 (C9H14ON+ = 4-methoxyphenethylammonium), by a combined experimental and theoretical approach. Our experiments demonstrate that (C9H14ON)2PbI4 shows a strong green emission under ambient conditions which is ascribed to its band gap of 2.4 eV. Moreover, our temperature-dependent photoluminescence (PL) experiments in the temperature range of 143–283 K reveal that the green emission red-shifts with increasing temperature, which is primarily attributed to the synergistic effect of thermal expansion and electron–phonon interactions. The elastic properties, obtained from density functional theory calculations, reveal that (C9H14ON)2PbI4 has relatively low modulus and anisotropy compared with other 2D materials.