Non-radiative recombination in Ge1−ySny light emitting diodes: The role of strain relaxation in tuned heterostructure designs

We demonstrate the highly efficient, GaN-based, multiple-quantum-well light-emitting diodes (LEDs) grown on Si (111) substrates embedded with the AlN buffer layer using NH3 growth interruption. Analysis of the materials by the X-ray diffraction omega scan and transmission electron microscopy revealed a remarkable improvement in the crystalline quality of the GaN layer with the AlN buffer layer using NH3 growth interruption. This improvement originated from the decreased dislocation densities and coalescence-related defects of the GaN layer that arose from the increased Al migration time. The photoluminescence peak positions and Raman spectra indicate that the internal tensile strain of the GaN layer is effectively relaxed without generating cracks. The LEDs embedded with an AlN buffer layer using NH3 growth interruption at 300 mA exhibited 40.9% higher light output power than that of the reference LED embedded with the AlN buffer layer without NH3 growth interruption. These high performances are attributed to an increased radiative recombination rate owing to the low defect density and strain relaxation in the GaN epilayer.

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Understanding the Role of Ion Migration in the Operation of Perovskite Light-Emitting Diodes by Transient Measurements

ACS Applied Materials & Interfaces ◽

10.1021/acsami.0c14269 ◽

2020 ◽

Vol 12 (43) ◽

pp. 48845-48853

Author(s):

Qi Dong ◽

Juliana Mendes ◽

Lei Lei ◽

Dovletgeldi Seyitliyev ◽

Liping Zhu ◽

...

Keyword(s):

Light Emitting Diodes ◽

Ion Migration ◽

Light Emitting ◽

Transient Measurements

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The Optical Properties of InGaN/GaN Nanorods Fabricated on (-201) β-Ga2O3 Substrate for Vertical Light Emitting Diodes

Photonics ◽

10.3390/photonics8020042 ◽

2021 ◽

Vol 8 (2) ◽

pp. 42

Author(s):

Jie Zhao ◽

Weijiang Li ◽

Lulu Wang ◽

Xuecheng Wei ◽

Junxi Wang ◽

...

Keyword(s):

Stark Effect ◽

Light Emitting Diodes ◽

Light Emitting Diode ◽

Strain Relaxation ◽

Blue Shift ◽

Peak Position ◽

Excitation Power ◽

Light Extraction Efficiency ◽

Excitation Power Density ◽

Light Emitting

We fabricated InGaN/GaN nanorod light emitting diode (LED) on (-201) β-Ga2O3 substrate via the SiO2 nanosphere lithography and dry-etching techniques. The InGaN/GaN nanorod LED grown on β-Ga2O3 can effectively suppress quantum confined Stark effect (QCSE) compared to planar LED on account of the strain relaxation. With the enhancement of excitation power density, the photoluminescence (PL) peak shows a large blue-shift for the planar LED, while for the nanorod LED, the peak position shift is small. Furthermore, the simulations also show that the light extraction efficiency (LEE) of the nanorod LED is approximately seven times as high as that of the planar LED. Obviously, the InGaN/GaN/β-Ga2O3 nanorod LED is conducive to improving the optical performance relative to planar LED, and the present work may lay the groundwork for future development of the GaN-based vertical light emitting diodes (VLEDs) on β-Ga2O3 substrate.

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