Green light-emitting diode from bromine based organic-inorganic halide perovskite

Abstract

Org anic-inorganic halide perovskites have attracted considerable attention owing to their outstanding solar cell efficiency. Meanwhile, these halide perovskites exhibit good light emitting in visible and near-infrared range with high fluorescence quantum yield, resulting in electroluminescence. However, it remains challenging for lighting and display due to the low luminance and poor long-term stability. Herein, high performance green light-emitting diodes are fabricated from bromine based perovskite (CH3NH3PbBr3) by systematically adjusting the preparation conditions and optimizing the emitting layer thickness. A high luminance up to 1500 cd m −2 (one of the highest values for perovskites-based light-emitting diodes) was achieved with 80 nm perovskites-emitting layer, due to the well-crystallized, full-coverage property of the films. This result further confirms the great prospect of organic-inorganic perovskites in optoelectronics.Recently, organic-inorganic halide perov skites, a new class of semiconductors with high power conversion efficiency and long-range balanced hole-electron transport characteristics, have shown huge potential in photovoltaics [1−10]. However, the work principle of these perovskite materials has not been well elucidated except for a few reports [11−15]. Apart from charge mobility [16,17], optical properties clearly point out another way to investigate these materials, which show pieces of information including charge separation, bandgap and chemical purity [18]. Interestingly, these organic-inorganic materials based on perovskites really exhibit excellent photoluminescence properties with tunable visible and near-infrared spectru m [19−22]. Moreover, combined with their balanced ambipolar properties, these materials have been proven to be electrically light emission. Very recently, a breakthrough in light-emitting diodes (LEDs) based on organic-inorganic halide perovskites has been made, which proves organic-inorganic halide perovskites as promising candidates in LEDs [23]. The ever reported LEDs based on these halide perovskites which show electroluminescence in near-infrared, red and green region and a luminance of ~364 cd m −2 was achieved 1 B eijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China 2 University of Chinese Academy of Sciences, Beijing 100190, China * Corresponding authors (emails: dhl522@iccas.ac.cn (Dong H); huwp@iccas.ac.cn (Hu W)) when the thickness of the active layer was 20 nm. Lately, an improved luminance of 417 cd m −2 was obtained for multicolored perovskites-LEDs based on a 40 nm emitter layer, which is due to the reduced carrier injection barrier for efficient electroluminescence [24]. However, further application remains challenging owing to the toxicity of Pb atom, poor long-term stability and low luminance. Thus, improving the luminance, which is the focus of this paper, emerges as an important and urgent aspect to make these LEDs commercialized.Acco...

A stable lead halide perovskite nanocrystals protected by PMMA

“…Recently, hybrid organic-inorganic lead halide perovskites (HOIPs) have aroused extensive interest due to their potential application in a wide variety of high-performance optoelectronic devices, including solar cells [1][2][3][4], light-emitting diodes [5][6][7], optically pumped lasers [8] and photodetectors [9,10]. However, HOIP materials suffer from poor stability under external stresses, especially moisture, heat and light, due to their low formation energy (approximate 0.1-0.3 eV) [11][12][13][14].…”

Mixtures of quasi-two and three dimensional hybrid organic-inorganic semiconducting perovskites for single layer LED

“…During the last two years, numerous research works related to perovskite LEDs have emerged, showing the immense possibilities of the perovskite materials due to their novel excitonic states. Important works 3 like these following, have shown the recombination kinetic relation to excitons and defect states [31], production of fluorene free perovskite LEDs [32], green light-emitting diode from bromine based organic-inorganic halide perovskite achieving light emissions of 1500cd m −2 [33] as well LEDs based on organometal halide perovskite amorphous nanoparticles with 3.8% efficiency [34]. Electronic properties of HOIS have been found to be partly dependent on their organic component [35], while quasi-2D HOIS have also been shown to have superb photovoltaic efficiencies [36].…”

Tuning crystal polymorphs of a π-extended tetrathiafulvalene-based cruciform molecule towards high-performance organic field-effect transistors

“…Functional organic molecules that may serve as the active components for organic electronics, such as organic field-effect transistors (OFETs), switches, or rectifiers has attracted wide interest in recent years [1][2][3][4]. Among them, tetrathiafuvalene (TTF), first discovered by Wudl et al [5] in 1970, has been seen as a promising building block for developing molecular electrical wires [6] and high performance organic semiconductors because of its unique redox-active properties, being reversibly oxidized in two one-electron steps [7][8][9][10] and having a nearly planar molecular structure and strong intermolecular π-π and S···S interactions facilitating charge transport.…”