Details

Autor(en) / Beteiligte

• Jeon, Sohee
• Zhao, Lianfeng
• Jung, Young‐Jin
• Kim, Ji Whan
• Kim, Sei‐Yong
• Kang, Hyeokjung
• Jeong, Jun‐Ho
• Rand, Barry P.
• Lee, Jeong‐Hwan

Titel

Perovskite Light‐Emitting Diodes with Improved Outcoupling Using a High‐Index Contrast Nanoarray

Ist Teil von

• Small (Weinheim an der Bergstrasse, Germany), 2019-02, Vol.15 (8), p.e1900135-n/a

Ort / Verlag

Germany: Wiley Subscription Services, Inc

Erscheinungsjahr

2019

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Organic–inorganic hybrid perovskite light‐emitting diodes (PeLEDs) are promising for next‐generation optoelectronic devices due to their potential to achieve high color purity, efficiency, and brightness. Although the external quantum efficiency (EQE) of PeLEDs has recently surpassed 20%, various strategies are being pursued to increase EQE further and reduce the EQE gap compared to other LED technologies. A key point to further boost EQE of PeLEDs is linked to the high refractive index of the perovskite emissive layer, leading to optical losses of more than 70% of emitted photons. Here, it is demonstrated that a randomly distributed nanohole array with high‐index contrast can effectively enhance outcoupling efficiency in PeLEDs. Based on a comprehensive optical analysis on the perovskite thin film and outcoupling structure, it is confirmed that the nanohole array effectively distributes light into the substrate for improved outcoupling, allowing for 1.64 times higher light extraction. As a result, highly efficient red/near‐infrared PeLEDs with a peak EQE of 14.6% are demonstrated. A highly efficient red/near‐infrared perovskite light‐emitting diode (PeLED) with a peak external quantum efficiency of 14.6% is demonstrated using a randomly distributed nanohole array (NHA) with high‐index contrast. The NHA properly compensates the disadvantage of high refractive index of the perovskite emissive layer without altering the PeLED structure, allowing for a 1.64‐times enhanced outcoupling.