Yb3+‐Doped Phenylethylammonium Lead Bromide 2D Layered Hybrid Perovskite for Near‐Infrared Emission.

Two‐dimensional (2D) layered hybrid perovskites like phenylethylammonium lead bromide [(PEA)2PbBr4] show interesting optoelectronic properties and improved moisture stability owing to the repeating quantum‐well structure and hydrophobic organic cations, respectively. Doping metal ions in such perovskites leads to exciton‐dopant interactions, imparting new optical properties. Here we report synthesis and optical properties of Yb3+‐doped (PEA)2PbBr4. Crystals show plate‐like morphology with lateral size of few micrometers. Also, ∼3.5 nm thin nanoplatelets are obtained after sonicating the samples. The host absorbs light via excitonic (and band‐band) transition at 407 nm. A part of the generated excitons recombines by emitting light at 414 nm along with host‐related non‐radiative recombination. Another significant part of the excitons recombines by non‐radiatively transferring the energy to the f‐electrons of Yb3+ dopant ions. The Yb3+ ions then de‐excite via f‐f (2F5/2→2F7/2) transition emitting near‐infrared (NIR) radiation with a peak at 997 nm. Such NIR‐emitting semiconductors with improved performances are desired for NIR light‐emitting diode applications. [ABSTRACT FROM AUTHOR]