Title: Low-efficiency-droop c -plane InGaN/GaN light-emitting diodes through the use of thick single quantum wells and doped barriers

Abstract

Efficiency droop at high current densities is a problem for InGaN-based light-emitting diodes (LEDs), especially for conventional c-plane devices. The large internal electric fields in c-plane quantum wells (QWs) lead to an increase in the active region carrier density ( n), causing the electrical efficiency droop onset to occur at low current densities. Here, we present an approach to reduce the internal electric fields ( E _int ) in c-plane QWs by placing doped p-type and n-type GaN barriers close to the QW. The reduced E _int also allows a thick QW active region design, which helps to lower n to further reduce the droop. The concept of using doped barriers to control E _int is explained using theory and device simulations. Following that, multiple series of thick single QW (SQW) LEDs were grown and characterized. Key parameters in the epitaxial design such as the doping levels and the relative position of the doped barriers were systematically studied and optimized. By using optimized doped barriers and a thick SQW, c-plane LEDs with a low-efficiency droop of 14% at 300 A/cm ² [with respect to the peak external quantum efficiency (EQE)] and a high peak EQE of 49% were demonstrated.

Authors:

Chow, Y. C.  ^[1];

• Search DOE PAGES for author "Chow, Y. C."
• Search DOE PAGES for ORCID "0000-0002-8926-0268"

Lynsky, C.  ^[1];

• Search DOE PAGES for author "Lynsky, C."
• Search DOE PAGES for ORCID "0000-0002-6895-9125"

Nakamura, S.  ^[2];

• Search DOE PAGES for author "Nakamura, S."
• Search DOE PAGES for ORCID "0000-0001-6334-2428"

DenBaars, S. P.  ^[2];

• Search DOE PAGES for author "DenBaars, S. P."
• Search DOE PAGES for ORCID "0000-0002-6612-5258"

Weisbuch, C.  ^[3];

• Search DOE PAGES for author "Weisbuch, C."
• Search DOE PAGES for ORCID "0000-0001-5403-5274"

Speck, J. S.  ^[1]

• Search DOE PAGES for author "Speck, J. S."
• Search DOE PAGES for ORCID "0000-0002-8045-4090"

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+ Show Author Affiliations

1. Materials Department, University of California, Santa Barbara, California 93106, USA
2. Materials Department, University of California, Santa Barbara, California 93106, USA, Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106, USA
3. Materials Department, University of California, Santa Barbara, California 93106, USA, Laboratoire de Physique de la Matière Condensée, École Polytechnique, CNRS, Institut Polytechnique de Paris, 91120 Palaiseau, France

Publication Date:

Fri Apr 14 00:00:00 EDT 2023

Sponsoring Org.:

USDOE

OSTI Identifier:

1968941

Grant/Contract Number:  

EE0008204; EE0009691; 2150283

Resource Type:

Publisher's Accepted Manuscript

Journal Name:

Journal of Applied Physics

Additional Journal Information:

Journal Name: Journal of Applied Physics Journal Volume: 133 Journal Issue: 14; Journal ID: ISSN 0021-8979

Publisher:

American Institute of Physics

Country of Publication:

United States

Language:

English