| Autor: |
Li, Ning, Han, Kevin, Spratt, William, Bedell, Stephen, Ott, John, Hopstaken, Marinus, Libsch, Frank, Li, Qinglong, Sadana, Devendra |
| Zdroj: |
Nature Photonics; Sep2019, Vol. 13 Issue 9, p588-592, 5p, 2 Diagrams, 2 Graphs |
| Abstrakt: |
Conventional light-emitting diodes (LEDs) face an efficiency droop at low current due to non-radiative recombination overtaking radiative recombination at low carrier density. To overcome this universal problem, we develop LEDs with high efficiency at ultralow current and voltage, using a novel quantum well design and high-quality interfaces to suppress non-radiative recombination and enhance radiative recombination. The device exhibits close to unity internal quantum efficiency at a low current density of <1 × 10−4 A cm−2, more than three orders of magnitude lower than conventional LEDs. The LED bias voltage is reduced to ~30% below the photon voltage (hν/q). Wireless communication is demonstrated at these low-power conditions, which enables new applications in smart dust and sensor networks1–6, low-cost block chain and authentication7–9, medical applications10,11 and wherever high efficiency at low power is needed. New phenomena such as high-efficiency electroluminescent cooling becomes possible as the LED unity internal quantum efficiency extends to smaller voltage and current. By using a single-quantum-well active region with a unique well–cladding design to suppress non-radiative recombination and enhance radiative recombination, light-emitting diodes with close to unity internal quantum efficiency at a low current density of <10−4 A cm−2 are demonstrated. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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