PMID- 29557788
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20191120
IS  - 1361-6528 (Electronic)
IS  - 0957-4484 (Linking)
VI  - 29
IP  - 23
DP  - 2018 Jun 8
TI  - Spectrally-resolved internal quantum efficiency and carrier dynamics of semipolar 
      [Formula: see text] core-shell triangular nanostripe GaN/InGaN LEDs.
PG  - 235206
LID - 10.1088/1361-6528/aab82e [doi]
AB  - We investigate the spectrally resolved internal quantum efficiency (IQE) and 
      carrier dynamics in semipolar [Formula: see text] core-shell triangular 
      nanostripe light-emitting diodes (TLEDs) using temperature-dependent 
      photoluminescence (TDPL) and time-resolved photoluminescence (TRPL) at various 
      excitation energy densities. Using electroluminescence, photoluminescence, and 
      cathodoluminescence measurements, we verify the origins of the broad emission 
      spectra from the nanostructures and confirm that localized regions of 
      high-indium-content InGaN exist along the apex of the nanostructures. Spectrally 
      resolved IQE measurements are then performed, with the spectra integrated from 
      400-450 nm and 450-500 nm to obtain the IQE of the QWs mainly near the sidewalls 
      and apex of the TLEDs, respectively. TDPL and TRPL are used to decouple the 
      radiative and non-radiative carrier lifetimes for different regions of the 
      emission spectra. We observe that the IQE is higher for the spectral region 
      between 450 nm and 500 nm compared to the IQE between 400 and 450 nm. This result 
      is in contrast to the typical observation that the IQE of planar GaN-based LEDs 
      is lower for longer wavelengths (i.e., higher indium contents). We also observe a 
      longer non-radiative recombination lifetime for the longer wavelength portion of 
      the spectrum. Several explanations are proposed for the improved IQE and longer 
      non-radiative lifetime observed near the apex of the nanostructures. The results 
      show that nanostructures may be leveraged to design more efficient green LEDs, 
      potentially addressing a long-standing challenge in GaN-based materials.
FAU - Okur, Serdal
AU  - Okur S
AD  - Center for High Technology Materials, University of New Mexico, Albuquerque, 
      United States of America.
FAU - Rishinaramangalam, Ashwin K
AU  - Rishinaramangalam AK
FAU - Mishkat-Ul-Masabih, Saadat
AU  - Mishkat-Ul-Masabih S
FAU - Nami, Mohsen
AU  - Nami M
FAU - Liu, Sheng
AU  - Liu S
FAU - Brener, Igal
AU  - Brener I
FAU - Brueck, Steven R J
AU  - Brueck SRJ
FAU - Feezell, Daniel F
AU  - Feezell DF
LA  - eng
PT  - Journal Article
DEP - 20180320
PL  - England
TA  - Nanotechnology
JT  - Nanotechnology
JID - 101241272
EDAT- 2018/03/21 06:00
MHDA- 2018/03/21 06:01
CRDT- 2018/03/21 06:00
PHST- 2018/03/21 06:00 [pubmed]
PHST- 2018/03/21 06:01 [medline]
PHST- 2018/03/21 06:00 [entrez]
AID - 10.1088/1361-6528/aab82e [doi]
PST - ppublish
SO  - Nanotechnology. 2018 Jun 8;29(23):235206. doi: 10.1088/1361-6528/aab82e. Epub 
      2018 Mar 20.