Current Spreading Length and Injection Efficiency in ZnO/GaN-Based Light-Emitting Diodes

Giuseppe Lullo, Roberto Macaluso, Isodiana Crupi, Mauro Mosca, Fulvio Caruso, Fulvio Caruso, Eric Feltin

Risultato della ricerca: Article

Abstract

We report on carrier injection features in light-emitting diodes (LEDs) based on nonintentionally doped-ZnO/p-GaN heterostructures. These LEDs consist of a ZnO layer grown by chemical-bath deposition (CBD) onto a p-GaN template without using any seed layer. The ZnO layer (∼1-µm thickness) consists of a dense collection of partially coalesced ZnO nanorods, organized in wurtzite phase with marked vertical orientation, whose density depends on the concentration of the solution during the CBD process. Due to the limited conductivity of the p-GaN layer, the recombination in the n-region is strongly dependent on the spreading length of the holes, Lh, coming from the p-contact. Moreover, the evaluation of Lh is not easy and generally requires the design and the fabrication of several LED test patterns. We propose a simple and effective method to calculate Lh, just based on simple considerations on I–V characteristics, and a way to improve the injection efficiency in the n region based on a noncircular electrode geometry. In particular, an interdigitated electrode structure is proved to be more efficient in terms of hole injection from n- to p-region.
Lingua originaleEnglish
pagine (da-a)4811-4816
Numero di pagine6
RivistaIEEE Transactions on Electron Devices
Volume66
Stato di pubblicazionePublished - 2019

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Light emitting diodes
Electrodes
Nanorods
Seed
Heterojunctions
Fabrication
Geometry

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

Cita questo

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title = "Current Spreading Length and Injection Efficiency in ZnO/GaN-Based Light-Emitting Diodes",
abstract = "We report on carrier injection features in light-emitting diodes (LEDs) based on nonintentionally doped-ZnO/p-GaN heterostructures. These LEDs consist of a ZnO layer grown by chemical-bath deposition (CBD) onto a p-GaN template without using any seed layer. The ZnO layer (∼1-µm thickness) consists of a dense collection of partially coalesced ZnO nanorods, organized in wurtzite phase with marked vertical orientation, whose density depends on the concentration of the solution during the CBD process. Due to the limited conductivity of the p-GaN layer, the recombination in the n-region is strongly dependent on the spreading length of the holes, Lh, coming from the p-contact. Moreover, the evaluation of Lh is not easy and generally requires the design and the fabrication of several LED test patterns. We propose a simple and effective method to calculate Lh, just based on simple considerations on I–V characteristics, and a way to improve the injection efficiency in the n region based on a noncircular electrode geometry. In particular, an interdigitated electrode structure is proved to be more efficient in terms of hole injection from n- to p-region.",
author = "Giuseppe Lullo and Roberto Macaluso and Isodiana Crupi and Mauro Mosca and Fulvio Caruso and Fulvio Caruso and Eric Feltin",
year = "2019",
language = "English",
volume = "66",
pages = "4811--4816",
journal = "IEEE Transactions on Electron Devices",
issn = "0018-9383",
publisher = "Institute of Electrical and Electronics Engineers Inc.",

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TY - JOUR

T1 - Current Spreading Length and Injection Efficiency in ZnO/GaN-Based Light-Emitting Diodes

AU - Lullo, Giuseppe

AU - Macaluso, Roberto

AU - Crupi, Isodiana

AU - Mosca, Mauro

AU - Caruso, Fulvio

AU - Caruso, Fulvio

AU - Feltin, Eric

PY - 2019

Y1 - 2019

N2 - We report on carrier injection features in light-emitting diodes (LEDs) based on nonintentionally doped-ZnO/p-GaN heterostructures. These LEDs consist of a ZnO layer grown by chemical-bath deposition (CBD) onto a p-GaN template without using any seed layer. The ZnO layer (∼1-µm thickness) consists of a dense collection of partially coalesced ZnO nanorods, organized in wurtzite phase with marked vertical orientation, whose density depends on the concentration of the solution during the CBD process. Due to the limited conductivity of the p-GaN layer, the recombination in the n-region is strongly dependent on the spreading length of the holes, Lh, coming from the p-contact. Moreover, the evaluation of Lh is not easy and generally requires the design and the fabrication of several LED test patterns. We propose a simple and effective method to calculate Lh, just based on simple considerations on I–V characteristics, and a way to improve the injection efficiency in the n region based on a noncircular electrode geometry. In particular, an interdigitated electrode structure is proved to be more efficient in terms of hole injection from n- to p-region.

AB - We report on carrier injection features in light-emitting diodes (LEDs) based on nonintentionally doped-ZnO/p-GaN heterostructures. These LEDs consist of a ZnO layer grown by chemical-bath deposition (CBD) onto a p-GaN template without using any seed layer. The ZnO layer (∼1-µm thickness) consists of a dense collection of partially coalesced ZnO nanorods, organized in wurtzite phase with marked vertical orientation, whose density depends on the concentration of the solution during the CBD process. Due to the limited conductivity of the p-GaN layer, the recombination in the n-region is strongly dependent on the spreading length of the holes, Lh, coming from the p-contact. Moreover, the evaluation of Lh is not easy and generally requires the design and the fabrication of several LED test patterns. We propose a simple and effective method to calculate Lh, just based on simple considerations on I–V characteristics, and a way to improve the injection efficiency in the n region based on a noncircular electrode geometry. In particular, an interdigitated electrode structure is proved to be more efficient in terms of hole injection from n- to p-region.

UR - http://hdl.handle.net/10447/386591

M3 - Article

VL - 66

SP - 4811

EP - 4816

JO - IEEE Transactions on Electron Devices

JF - IEEE Transactions on Electron Devices

SN - 0018-9383

ER -