Violet light excitable organic halides with short ∼ns emissions for multiple optoelectronic applications†

Abstract

Phosphors, with the properties of being excitable by relatively low energy (violet-light) and having short photoluminescence (PL) lifetime (∼ns), could be used in some special optoelectronic fields, such as violet-light excitable green lighting and optical communications. In this work, we synthesized eight organic halides (four new compounds) by introducing halogen atoms into aromatic molecules with non-planar structures. The as-synthesized compounds could be efficiently excited by violet lights of 400–420 nm. They also exhibited fast PL decay with a minimum PL lifetime of 1.79 ns. Based on the as-explored materials, a phosphor-converted light-emitting diode was assembled onto a 400 nm violet chip, emitting bright white light with a low color temperature (4377 K) and a high color rendering index (90.3). Due to the fast PL decay feature, we successfully used the as-discovered organic halides for visible light communication. The photoelectric detector collects the optical signal emitted by the phosphor-converted light emitting diode (pc-LED) fabricated by the compound, and transmits it to the oscilloscope. In the transmission rate range of 10–33 Mbps, a clear opened-eye diagram is observed, indicating the high communication capability of the compound. The −3 dB bandwidth is determined to be 22.1 MHz, surpassing those of most perovskite halides and commercial phosphors. This work highlights the significance of the organic halides towards green lighting and information transmission.