Directional Polarized Light Emission from Thin-Film Light-Emitting Diodes
| Autor: | Lei Lei, Franky So, Juliana Mendes, Siliang He, Renuka Gogusetti, Shichen Yin, Xiangyu Fu, Yi-An Chen, Yash Mehta, Nilesh Barange, Liping Zhu, Chih-Hao Chang, Qi Dong |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Extinction ratio business.industry Mechanical Engineering Physics::Optics 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Polarization (waves) 01 natural sciences 0104 chemical sciences law.invention Mechanics of Materials law Optoelectronics General Materials Science Light emission Photonics 0210 nano-technology business Waveguide Diode Perovskite (structure) Light-emitting diode |
| Zdroj: | Advanced materials (Deerfield Beach, Fla.). 33(9) |
| ISSN: | 1521-4095 |
| Popis: | Light-emitting diodes (LEDs) with directional and polarized light emission have many photonic applications, and beam shaping of these devices is fundamentally challenging because they are Lambertian light sources. In this work, using organic and perovskite LEDs (PeLEDs) for demonstrations, by selectively diffracting the transverse electric (TE) waveguide mode while suppressing other optical modes in a nanostructured LED, the authors first demonstrate highly directional light emission from a full-area organic LED with a small divergence angle less than 3° and a TE to transverse magnetic (TM) polarization extinction ratio of 13. The highly selective diffraction of only the TE waveguide mode is possible due to the planarization of the device stack by thermal evaporation and solution processing. Using this strategy, directional and polarized emission from a perovskite LED having a current efficiency 2.6 times compared to the reference planar device is further demonstrated. This large enhancement in efficiency in the PeLED is attributed to a larger contribution from the TE waveguide mode resulting from the high refractive index in perovskite materials. |
| Databáze: | OpenAIRE |
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