Effects of Artificial Light Treatments on Growth, Mineral Composition, Physiology, and Pigment Concentration in Dieffenbachia maculata “Compacta” Plants

Specific wavebands may allow precise control of plant growth. However, light sources must be carefully evaluated before the large-scale use of supplemental light sources can be implemented. Dieffenbachia maculata “Compacta” plants were grown for 8 weeks in pots in a growth chamber under tightly controlled temperature and humidity in order to assess the effects of supplemental light. Three treatments were applied: (i) using 18-W fluorescent bulbs (T1), (ii) using the same bulbs with supplemental light emitting diodes (LEDs) (Pure Blue and Pure Red Mix-Light-Emitting Diodes (BR-LEDs)) (T2), and (iii) using high-efficiency TL5 fluorescents (T3). Plant biomass, mineral composition, and physiological and photosynthetic parameters were assessed under each light treatment. Total plant dry weight was highest in plants grown under treatments T1 and T3. Other differences were observed between different light treatments, including variation in biomass partitioning as well as N and K concentrations in roots, stems, and leaves. Further, proline and indole 3-acetic acid (IAA) levels were higher in plants grown under the T1 treatment, whereas total soluble sugars and starch were higher in plants grown under treatment T3. Plants grown under treatment T1 had the lowest chlorophyll concentrations. No differences were observed in organ water content and P concentration. T2 was not the best treatment, as expected. The model proposed a linear regression between integrated use of spectral energy (IUSE) and total dry weight (TDW), which showed a good relationship with an R2 value of 0.83. Therefore, we recommend this methodology to discern the effects of the different spectral qualities on plant biomass.

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Fittonia verschaffeltii Response to Artificial Light Treatments: BIOMASS, Nutrient Concentrations and Physiological Changes

Agronomy ◽

10.3390/agronomy10010126 ◽

2020 ◽

Vol 10 (1) ◽

pp. 126 ◽

Cited By ~ 1

Author(s):

Pedro García-Caparros ◽

Eva María Almansa ◽

Francisco Javier Barbero ◽

Rosa María Chica ◽

María Teresa Lao

Keyword(s):

Plant Biomass ◽

Soluble Sugars ◽

Dry Weight ◽

Experimental Period ◽

Physiological Parameters ◽

Nutrient Concentrations ◽

Spectral Energy ◽

Light Emitting ◽

Total Plant ◽

Total Dry Weight

The purpose of the present study was to evaluate the effects of different light treatments on biomass, nutrient concentrations and physiological parameters of Fittonia verschaffeltii (Lem) Van Houtte. The aim was to establish a methodology to evaluate the effect of photosynthetically active radiation (PAR) emitted by lamps on biomass. The light treatments used were tube luminescent Dunn (TL-D), tube luminescent Dunn + light emitting diodes (LEDs) and Tube luminescent 5 (TL-5). At the end of the experimental period, biomass, nutritional, biochemical, and physiological parameters were assessed. A clear reduction in total plant dry weight under TL-D + LEDs at the end of the experiment was recorded. With respect to nutrient concentration in the different organs assessed, there was no clear response under the different light treatments. The growth under TL-D lamps resulted in the highest concentration of total soluble sugars and starch in leaves, whereas the highest value of indole 3-acetic acid concentration was under TL-5 lamps. Plants grown under TL-D + LEDs showed the lowest values of chlorophyll a, b and a + b. The relationship proposed between integrated use of spectral energy (IUSE) and total dry weight (TDW) showed a good correlation with an R2 value of 0.86, therefore we recommend this methodology to discern the effects of the different spectral qualities on plant biomass.

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Light Intensity and Quality from Sole-source Light-emitting Diodes Impact Growth, Morphology, and Nutrient Content of Brassica Microgreens

HortScience ◽

10.21273/hortsci.51.5.497 ◽

2016 ◽

Vol 51 (5) ◽

pp. 497-503 ◽

Cited By ~ 14

Author(s):

Joshua R. Gerovac ◽

Joshua K. Craver ◽

Jennifer K. Boldt ◽

Roberto G. Lopez

Keyword(s):

Light Emitting Diodes ◽

Dry Weight ◽

Nutrient Content ◽

Sole Source ◽

Photon Flux ◽

Light Sources ◽

Growth Morphology ◽

Hypocotyl Length ◽

Photoelectric Conversion ◽

Light Emitting

Multilayer vertical production systems using sole-source (SS) lighting can be used for the production of microgreens; however, traditional SS lighting methods can consume large amounts of electrical energy. Light-emitting diodes (LEDs) offer many advantages over conventional light sources, including high photoelectric conversion efficiencies, narrowband spectral light quality (LQ), low thermal output, and adjustable light intensities (LIs). The objective of this study was to quantify the effects of SS LEDs of different light qualities and intensities on growth, morphology, and nutrient content of Brassica microgreens. Purple kohlrabi (Brassica oleracea L. var. gongylodes L.), mizuna (Brassica rapa L. var. japonica), and mustard [Brassica juncea (L.) Czern. ‘Garnet Giant’] were grown in hydroponic tray systems placed on multilayer shelves in a walk-in growth chamber. A daily light integral (DLI) of 6, 12, or 18 mol·m−2·d−1 was achieved from commercially available SS LED arrays with light ratios (%) of red:green:blue 74:18:8 (R74:G18:B8), red:blue 87:13 (R87:B13), or red:far-red:blue 84:7:9 (R84:FR7:B9) with a total photon flux (TPF) from 400 to 800 nm of 105, 210, or 315 µmol·m−2·s−1 for 16 hours. Regardless of LQ, as the LI increased from 105 to 315 µmol·m−2·s−1, hypocotyl length (HL) decreased and percent dry weight (DW) increased for kohlrabi, mizuna, and mustard microgreens. With increasing LI, leaf area (LA) of kohlrabi generally decreased and relative chlorophyll content (RCC) increased. In addition, nutrient content increased under low LIs regardless of LQ. The results from this study can help growers to select LIs and LQs from commercially available SS LEDs to achieve preferred growth characteristics of Brassica microgreens.

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High Efficiency Green Quantum Dot Light-Emitting Diodes with Surface-treated Indium Phosphide

Proceedings of the International Display Workshops ◽

10.36463/idw.2019.oledp2-4 ◽

2019 ◽

pp. 940

Author(s):

Wei Jiang ◽

Hee Yeop Chae

Keyword(s):

Quantum Dot ◽

Indium Phosphide ◽

High Efficiency ◽

Light Emitting Diodes ◽

Light Emitting

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Dendritic Self-Host Phosphorescent Iridium Materials for High-Efficiency Organic Light-Emitting Diodes

Current Organic Chemistry ◽

10.2174/1385272821666170830115628 ◽

2018 ◽

Vol 22 (6) ◽

pp. 590-599 ◽

Cited By ~ 2

Author(s):

Chuang Yao ◽

Cuifeng Jiang ◽

Jinshan Wang

Keyword(s):

High Efficiency ◽

Light Emitting Diodes ◽

Organic Light Emitting Diodes ◽

Light Emitting ◽

Organic Light

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High-efficiency, long-lifetime deep-blue organic light-emitting diodes

Nature Photonics ◽

10.1038/s41566-021-00763-5 ◽

2021 ◽

Vol 15 (3) ◽

pp. 208-215 ◽

Cited By ~ 1

Author(s):

Soon Ok Jeon ◽

Kyung Hyung Lee ◽

Jong Soo Kim ◽

Soo-Ghang Ihn ◽

Yeon Sook Chung ◽

...

Keyword(s):

High Efficiency ◽

Light Emitting Diodes ◽

Organic Light Emitting Diodes ◽

Light Emitting ◽

Deep Blue ◽

Organic Light ◽

Long Lifetime

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High efficiency blue organic light-emitting diodes with below-bandgap electroluminescence

Nature Communications ◽

10.1038/s41467-021-25135-z ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Maria Vasilopoulou ◽

Abd. Rashid bin Mohd Yusoff ◽

Matyas Daboczi ◽

Julio Conforto ◽

Anderson Emanuel Ximim Gavim ◽

...

Keyword(s):

High Efficiency ◽

Light Emitting Diodes ◽

High Mobility ◽

Organic Light Emitting Diodes ◽

Triplet Energy ◽

Material Interface ◽

Light Emitting ◽

Thermally Activated ◽

Organic Light ◽

Hole Transporting

AbstractBlue organic light-emitting diodes require high triplet interlayer materials, which induce large energetic barriers at the interfaces resulting in high device voltages and reduced efficiencies. Here, we alleviate this issue by designing a low triplet energy hole transporting interlayer with high mobility, combined with an interface exciplex that confines excitons at the emissive layer/electron transporting material interface. As a result, blue thermally activated delay fluorescent organic light-emitting diodes with a below-bandgap turn-on voltage of 2.5 V and an external quantum efficiency (EQE) of 41.2% were successfully fabricated. These devices also showed suppressed efficiency roll-off maintaining an EQE of 34.8% at 1000 cd m−2. Our approach paves the way for further progress through exploring alternative device engineering approaches instead of only focusing on the demanding synthesis of organic compounds with complex structures.

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Application of Light-Emitting Diodes for Improving the Nutritional Quality and Bioactive Compound Levels of Some Crops and Medicinal Plants

Molecules ◽

10.3390/molecules26051477 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1477

Author(s):

Woo-Suk Jung ◽

Ill-Min Chung ◽

Myeong Ha Hwang ◽

Seung-Hyun Kim ◽

Chang Yeon Yu ◽

...

Keyword(s):

Plant Growth ◽

In Vitro Culture ◽

Light Emitting Diodes ◽

Photosynthetic Pigment ◽

Antioxidant Properties ◽

Light Sources ◽

Light Emitting ◽

Cell Defense ◽

Led Irradiation

Light is a key factor that affects phytochemical synthesis and accumulation in plants. Due to limitations of the environment or cultivated land, there is an urgent need to develop indoor cultivation systems to obtain higher yields with increased phytochemical concentrations using convenient light sources. Light-emitting diodes (LEDs) have several advantages, including consumption of lesser power, longer half-life, higher efficacy, and wider variation in the spectral wavelength than traditional light sources; therefore, these devices are preferred for in vitro culture and indoor plant growth. Moreover, LED irradiation of seedlings enhances plant biomass, nutrient and secondary metabolite levels, and antioxidant properties. Specifically, red and blue LED irradiation exerts strong effects on photosynthesis, stomatal functioning, phototropism, photomorphogenesis, and photosynthetic pigment levels. Additionally, ex vitro plantlet development and acclimatization can be enhanced by regulating the spectral properties of LEDs. Applying an appropriate LED spectral wavelength significantly increases antioxidant enzyme activity in plants, thereby enhancing the cell defense system and providing protection from oxidative damage. Since different plant species respond differently to lighting in the cultivation environment, it is necessary to evaluate specific wavebands before large-scale LED application for controlled in vitro plant growth. This review focuses on the most recent advances and applications of LEDs for in vitro culture organogenesis. The mechanisms underlying the production of different phytochemicals, including phenolics, flavonoids, carotenoids, anthocyanins, and antioxidant enzymes, have also been discussed.

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Electrically driven single microribbon based near-infrared exciton-polariton light-emitting diode

CrystEngComm ◽

10.1039/d1ce00419k ◽

2021 ◽

Author(s):

Mingming Jiang ◽

Fupeng Zhang ◽

Kai Tang ◽

Peng Wan ◽

Caixia Kan

Keyword(s):

High Performance ◽

Near Infrared ◽

Light Emitting Diodes ◽

Light Emitting Diode ◽

Light Sources ◽

Coherent Light ◽

Light Emitting ◽

Exciton Polaritons ◽

Laser Devices

Achieving electrically-driven exciton-polaritons has drawn substantial attention toward developing ultralow-threshold coherent light sources, containing polariton laser devices and high-performance light-emitting diodes (LEDs). In this work, we demonstrate an electrically driven...

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Efficient and large-area all vacuum-deposited perovskite light-emitting diodes via spatial confinement

Nature Communications ◽

10.1038/s41467-021-25093-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Peipei Du ◽

Jinghui Li ◽

Liang Wang ◽

Liang Sun ◽

Xi Wang ◽

...

Keyword(s):

High Resolution ◽

Large Scale ◽

High Efficiency ◽

Light Emitting Diodes ◽

Scale Production ◽

Nonradiative Recombination ◽

Large Area ◽

Spatial Confinement ◽

Light Emitting ◽

Large Scale Production

AbstractWith rapid advances of perovskite light-emitting diodes (PeLEDs), the large-scale fabrication of patterned PeLEDs towards display panels is of increasing importance. However, most state-of-the-art PeLEDs are fabricated by solution-processed techniques, which are difficult to simultaneously achieve high-resolution pixels and large-scale production. To this end, we construct efficient CsPbBr3 PeLEDs employing a vacuum deposition technique, which has been demonstrated as the most successful route for commercial organic LED displays. By carefully controlling the strength of the spatial confinement in CsPbBr3 film, its radiative recombination is greatly enhanced while the nonradiative recombination is suppressed. As a result, the external quantum efficiency (EQE) of thermally evaporated PeLED reaches 8.0%, a record for vacuum processed PeLEDs. Benefitting from the excellent uniformity and scalability of the thermal evaporation, we demonstrate PeLED with a functional area up to 40.2 cm2 and a peak EQE of 7.1%, representing one of the most efficient large-area PeLEDs. We further achieve high-resolution patterned perovskite film with 100 μm pixels using fine metal masks, laying the foundation for potential display applications. We believe the strategy of confinement strength regulation in thermally evaporated perovskites provides an effective way to process high-efficiency and large-area PeLEDs towards commercial display panels.

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