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.

Macaluso, R., Lullo, G., Crupi, I., Caruso, F., Feltin, E., Mosca, M. (2019). Current Spreading Length and Injection Efficiency in ZnO/GaN-Based Light-Emitting Diodes. IEEE TRANSACTIONS ON ELECTRON DEVICES, 66(11), 4811-4816 [10.1109/TED.2019.2942183].

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

Macaluso, Roberto;Lullo, Giuseppe;Crupi, Isodiana;Mosca, Mauro
2019-01-01

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.
Settore ING-INF/01 - Elettronica
Macaluso, R., Lullo, G., Crupi, I., Caruso, F., Feltin, E., Mosca, M. (2019). Current Spreading Length and Injection Efficiency in ZnO/GaN-Based Light-Emitting Diodes. IEEE TRANSACTIONS ON ELECTRON DEVICES, 66(11), 4811-4816 [10.1109/TED.2019.2942183].
File in questo prodotto:
File Dimensione Formato  
Submission proof.pdf

accesso aperto

Descrizione: Articolo principale
Tipologia: Post-print
Dimensione 2.86 MB
Formato Adobe PDF
2.86 MB Adobe PDF Visualizza/Apri
current.pdf

Solo gestori archvio

Tipologia: Versione Editoriale
Dimensione 1.11 MB
Formato Adobe PDF
1.11 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10447/386591
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 4
  • ???jsp.display-item.citation.isi??? 4
social impact