Perovskites for Optoelectronics

Light emission

High performance from extraordinarily thick organic light-emitting diodes

Toshinori Matsushima et al., Nature 572, 502-506 (2019) doi:10.1038/s41586-019-1435-5

Thick organic electronics: Light-emitted diodes made from organic materials (OLEDs) are now an integral component of many electronic devices and could underpin next-generation displays and lighting due to their low cost, ease of processing and flexibility. One issue that frequently arises for this technology, however, is ensuring a uniform covering of organic layers when using large substrates. This can be overcome by using thicker layers but this generally reduces the carrier mobility, so requires larger driving voltages. Chihaya Adachi and colleagues now demonstrate that extraordinarily thick OLEDs can be fabricated using hybrid organic-inorganic perovskites as the transport layers. The high carrier mobilities in such materials allows the thickness to be increase by more than ten-times that of standard OLEDs, without sacrificing voltage, efficiency or durability, and could be exploited in other organic devices. Shareable link

Rational molecular passivation for high-performance perovskite light-emitting diodes

Hoyeon Kin et al., Nat. Photon. 13, 418-423 (2019) doi:10.1038/s41566-019-0390-x

Improved understanding of passivation leads to near-infrared perovskite light-emitting diodes with 21.6% external quantum efficiency. Shareable link

Hybrid perovskite light emitting diodes under intense electrical excitation

Hoyeon Kin et al., Nat. Commun. 9, 4893 (2018) doi:10.1038/s41467-018-07383-8

Hybrid perovskite semiconductors are promising for wavelength-tunable laser diodes but their behavior under intense electrical excitation remains unexplored. Kim et al. investigate perovskite light emitting diodes at current densities nearing 1 kA cm^-2 and suggest that a laser diode is within reach. 

High-efficiency perovskite–polymer bulk heterostructure light-emitting diodes

Baodan Zhao et al., Nat. Photon. 562, 783-789 (2018) doi:10.1038/s41566-018-0283-4

Near-infrared perovskite–polymer light-emitting diodes (LEDs) with external quantum efficiencies of up to 20.1% are reported. Shareable link

Perovskite light-emitting diodes with external quantum efficiency exceeding 20 per cent

Kebin Lin et al., Nature 562, 245-248 (2018) doi:10.1038/s41586-018-0575-3

The impressive optoelectronic properties of metal halide pervoskites make them promising candidates for developing low-cost solar cell technologies. These properties, however, also make them interesting for light-emitting applications such as flat-panel display, but their efficiencies are too low to be competitive. Jianpu Wang and colleagues show that the formation of submicron structures can raise the external quantum efficiencies beyond the milestone of 20%, taking an important step towards practical applications of pervoskite-based devices in lighting and displays. Shareable link

Perovskite light-emitting diodes based on spontaneously formed submicrometre-scale structures

Yu Cao et al., Nature 562, 249-253 (2018) doi:10.1038/s41586-018-0576-2

The impressive optoelectronic properties of metal halide pervoskites make them promising candidates for developing low-cost solar cell technologies. These properties, however, also make them interesting for light-emitting applications such as flat-panel display, but their efficiencies are too low to be competitive. Jianpu Wang and colleagues show that the formation of submicron structures can raise the external quantum efficiencies beyond the milestone of 20%, taking an important step towards practical applications of pervoskite-based devices in lighting and displays. Shareable link

Color-stable highly luminescent sky-blue perovskite light-emitting diodes

Jun Xing et al., Nat. Commun. 9, 3541 (2018) doi:10.1038/s41467-018-05909-8

Perovskite light-emitting diodes show promising color tunability and device performance but suffer from emission color shift at higher driving voltages. Here Xing et al. report color stable blue light-emitting diodes by drastically increasing the phase purity of the quasi-2D perovskite thin films. Shareable link

From the archive

Color-Stable Highly Luminescent Sky-Blue Perovskite Light-emitting Diodes

Jun Xing et al., Nat. Commun. 9, 3541 (2018) doi:10.1038/s41467-018-05909-8

Perovskite light-emitting diodes show promising color tunability and device performance but suffer from emission color shift at higher driving voltages. Here Xing et al. report color stable blue light-emitting diodes by drastically increasing the phase purity of the quasi-2D perovskite thin films. Shareable link

Electron–phonon interaction in efficient perovskite blue emitters

Xiwen Gong et al., Nat. Mater. 17, 550-556 (2018) doi:10.1038/s41563-018-0081-x

Films of exfoliated crystals of two-dimensional hybrid metal halide perovskites with phenyl groups as organic cations show increased molecular rigidity, reduced electron–phonon interactions and blue emission with photoluminescence quantum yield approaching 80%. Shareable link

Maximizing and stabilizing luminescence from halide perovskites with potassium passivation

Mojtaba Abdi-Jalebi et al., Nature 555, 497-501 (2018) doi:10.1038/nature25989

Decoration of the surfaces and grain boundaries of perovksites with passivating potassium halide layers is shown to reduce parasitic non-radiative losses and photo-induced ion migration — two key causes of low luminescence yields. This approach, applied to a wide range of mixed halide perovskites, yielded luminescence approaching the efficiency limits and improved the charge transport and interfaces with device electrodes. Shareable link

Minimising efficiency roll-off in high-brightness perovskite light-emitting diodes

Wei Zou et al., Nat. Commun. 9, 608 (2018) doi:10.1038/s41467-018-03049-7

Large drop in efficiency at high brightness has been holding back the development of various light-emitting diodes including halide perovskite. Here Zou et al. achieve high quantum efficiency of 10% under a high current density of 500 mA cm-2 in perovskite based diodes by reducing luminescence quenching.

Bright triplet excitons in caesium lead halide perovskites

Michael A. Becker et al., Nature 553, 189-193 (2018) doi:10.1038/nature25147

Excitons are the electronic excitations that are ultimately responsible for the emissive properties of nanostructured semiconductors, and prevailing wisdom is that the lowest-energy excitonic state will be long-lived and hence poorly emitting (or 'dark'). Michael Becker et al. now show that caesium lead halide perovskites disobey this rule: the lowest-energy excitons are instead unusually 'bright', emitting much faster than any other semiconductor nanocrystal. Shareable link

Ultra-bright and highly efficient inorganic based perovskite light-emitting diodes 

Liuqi Zhang et al., Nat. Commun. 8 15640 (2017) doi:10.1038/ncomms15640

Hybrid organic-inorganic perovskite are garnering attention for light emitting diode (LED) applications. Employing a thin hydrophilic insulating polymer, Zhang et al., report LEDs exhibiting a brightness of 91000 cd m-2 and external quantum efficiency of 10.4% using a mixed-cation perovskite.

Efficient perovskite light-emitting diodes featuring nanometre-sized crystallites

Zhengguo Xiao et al., Nat. Photon. 11, 108-115 (2017), doi:10.1038/nphoton.2016.269

Perovskite nanocrystal LEDs featuring long-chain ammonium cations offer improved stability and efficiency. Shareable Link

Perovskite light-emitting diodes based on solution-processed self-organized multiple quantum wells

Nana Wang et al., Nat. Photon. 10, 699-704 (2016), doi:10.1038/nphoton.2016.185

Perovskite quantum wells yield highly efficient LEDs spanning the visible and near-infrared. Shareable Link

Perovskite energy funnels for efficient light-emitting diodes

Mingjian Yuan et al., Nat. Nanotechnol. 11, 872-877 (2016), doi:10.1038/nnano.2016.110

Light-emitting diodes based on mixed-dimensionality perovskite solids show outstanding radiative properties in the near-infrared region. Shareable Link

Highly efficient quantum dot near-infrared light emitting diodes

Xiwen Gong et al., Nat. Photon. 10, 253-257 (2016), doi:10.1038/nphoton.2016.11

Lead halide perovskite colloidal nanocrystals have promising optoelectronic properties, such as high photoluminescence quantum yields and narrow emission linewidths. Here, the authors report low-threshold amplified spontaneous emission and two kinds of lasing in nanostructured caesium lead halide perovskites.

Lead halide perovskite nanowire lasers with low lasing thresholds and high quality factors

Haiming Zhu et al., Nat. Mater. 14, 636-642 (2015), doi:10.1038/nmat4271

A surface-initiated solution growth method is used to synthesize single-crystal nanowires of organic–inorganic perovskite that show very low lasing threshold. Coating the nanowires with metallic films marginally affects the lasing performance. Shareable Link