Recent Advancements in Near-Infrared Perovskite Light-Emitting Diodes

Abstract

Metal halide perovskites have shown excellent properties for lighting applications, including high photoluminescence quantum yield (PLQY), compositional tunability, and narrow emission line widths. Perovskite light-emitting diodes (LEDs) have achieved external quantum efficiency (EQE) up to 20% in the green, red, and near-infrared (NIR) spectral regions. Recently, nanostructured perovskite NIR-LEDs have displayed 100 h of device stability, making this technology commercially viable and prompting greater awareness of this class of devices, as distinct from visible wavelength perovskite LEDs. Even so, the current generation of high-performance perovskite LEDs are still hampered by slow radiative recombination of charge carriers, unbalanced injection of charge carriers, and light out-coupling efficiency; therefore, more structural and morphological engineering of perovskite LEDs is needed to confine the charge carriers and collect the photons more effectively. It has been observed that 3D bulk perovskites show high performance but have poor stability and offer less control over their optical properties. In contrast, NIR-emitting perovskite nanocrystals offer precise control of their optical properties but exhibit poor optoelectronic properties due to the presence of bulky ligands. Quasi-2D perovskite systems have gained significant attention as they balance high conductivity and stability, while enabling precise color tuning of nanostructures, and the possibility to produce single crystal-LEDs. Here, we assess these and other recent advancements in NIR-emitting perovskite materials. We compare different structural frameworks and how they influence the LED performance in terms of color stability, EQE, and device stability. The practical challenges facing each of these structural classes of perovskite NIR-LED materials and the possible strategies to overcome these obstacles are thoroughly discussed.

Halide Perovskite Nanocrystal Emitters

“…[ 97 ] This has led to an increased interest in NIR‐emitting perovskites and corresponding devices. [ 98 ] The most intensively studied and well‐established PNCs have the PL band in the visible spectral region that limits their use in a variety of photonic and optoelectronic applications. This problem requires searching for new strategies for PNC synthesis to extend the PL bands to longer wavelengths, i.e., in the NIR range.…”

In-Situ Nano-Auger Probe of Chloride-Ions during CH3NH3PbI3−xClx Perovskite Formation

“…Importantly, carrier diffusion length and band gap of MAPbI 3 are controlled by compositional engineering. The fine control over optoelectronic properties and ease of synthesis has driven MAPbI 3 to broad applications, including PSCs [ 11 ], solar-water splitting [ 12 ], lasing [ 13 ], and light-emitting diodes [ 14 ]. In addition, the incorporation of a small amount of bromine or chlorine into MAPbI 3 is known to improve device properties [ 15 ].…”

Research progress of full electroluminescent white light-emitting diodes based on a single emissive layer

“…Perovskite emitters have become desirable materials in recent years because of their excellent photoelectric properties, such as their high photoluminescence quantum yields (PLQYs) and bipolar carrier mobility, and they have great potential in lighting and displays 67 – 74 . Many PeLEDs have been demonstrated with EQEs higher than 20% in the green 75 – 77 , red 78 , 79 , and near-infrared 80 – 82 regions. In addition to these exciting results, WPeLEDs, especially SEL–WPeLEDs, have also been developed rapidly 26 – 29 , 83 – 87 .…”