Three-Dimensional Imaging of Extended Defects in 4H-SiC by Two-Photon-Excited Band-Edge Photoluminescence

2015 ◽  
Vol 821-823 ◽  
pp. 343-346 ◽  
Author(s):  
Ryohei Tanuma ◽  
Hidekazu Tsuchida
Keyword(s):  
Three Dimensional ◽  
Band Edge ◽  
Band Edge Emission ◽  
Extended Defects ◽  
Edge Emission ◽  
Three Dimensional Imaging ◽  
Two Photon ◽  
Propagation Behavior ◽  
Excited Band ◽  
Edge Dislocations

This paper demonstrates three-dimensional imaging of threading screw dislocations (TSDs) and threading edge dislocations (TEDs) in 4H-SiC using two-photon-excited photoluminescence (2PPL) band-edge emission. Three-dimensional (3D) images of TSDs and TEDs are successfully obtained as dark contrasts on a bright background of band-edge emission. The intensity inversion of a 2PPL 3D image yields a perspective to visually examine the propagation behavior of dislocations. The tilt angles of TEDs are also measured and shown to correlate with the directions of the extra half planes of TEDs.

Three-Dimensional Imaging of Extended Defects in 4H-SiC

2016 ◽  
Vol 858 ◽  
pp. 361-366 ◽  
Author(s):  
Ryohei Tanuma ◽  
Masahiro Nagano ◽  
Isaho Kamata ◽  
Hidekazu Tsuchida
Keyword(s):  
3D Imaging ◽  
Second Harmonic ◽  
Three Dimensional ◽  
Stacking Faults ◽  
Band Edge Emission ◽  
Extended Defects ◽  
Edge Emission ◽  
3D Images ◽  
Two Photon ◽  
Edge Dislocations

This paper describes 3D imaging of extended defects in 4H-SiC using optical second-harmonic generation (SHG) and two-photon-exited photoluminescence (2PPL). SHG selectively yields the 3D images of 3C-inclusions in a 4H-SiC epilayer, while 2PPL provides 3D images of 3C-inclusions, 8H stacking faults and single Shockley stacking faults. 2PPL band-edge emission visualizes dislocation lines of threading screw dislocations and threading edge dislocations, the tilt angles of which are evaluated.

Three-dimensional imaging and tilt-angle analysis of dislocations in 4H-SiC by two-photon-excited band-edge photoluminescence

2014 ◽  
Vol 7 (12) ◽  
pp. 121303 ◽  
Author(s):  
Ryohei Tanuma ◽  
Masahiro Nagano ◽  
Isaho Kamata ◽  
Hidekazu Tsuchida
Keyword(s):  
Tilt Angle ◽  
Three Dimensional ◽  
Band Edge ◽  
Three Dimensional Imaging ◽  
Two Photon ◽  
Excited Band

Three-Dimensional Imaging of Extended Defects in 4H-SiC by Optical Second-Harmonic Generation

2014 ◽  
Vol 778-780 ◽  
pp. 338-341 ◽  
Author(s):  
Ryohei Tanuma ◽  
Hidekazu Tsuchida
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Basal Plane ◽  
Second Harmonic ◽  
Three Dimensional ◽  
Extended Defects ◽  
Host Crystal ◽  
Three Dimensional Imaging ◽  
Two Photon ◽  
Optical Second Harmonic Generation

This paper demonstrates optical second-harmonic generation (SHG) and two-photon excited photoluminescence (2P-PL) imaging of 3C-SiC inclusions forming triangular and carrot-type defects in 4H-SiC epilayers. Triangular defects exhibit clear SHG images because 3C-SiC is SHG active, but not 4H-SiC host crystal in c-axis incidence. A carrot defect provides SHG and 2P-PL images in different regions in a basal-plane fault area. The spectrums of the SHG and 2P-PL are also investigated, and their emission mechanisms discussed.

scholarly journals Core Nanoparticle Engineering for Narrower and More Intense Band-Edge Emission from AgInS2/GaSx Core/Shell Quantum Dots

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1763 ◽  
Author(s):  
Watcharaporn Hoisang ◽  
Taro Uematsu ◽  
Takahisa Yamamoto ◽  
Tsukasa Torimoto ◽  
Susumu Kuwabata
Keyword(s):  
Surface Passivation ◽  
Precursor Solution ◽  
Silver Sulfide ◽  
Band Edge ◽  
Crystal Phase ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Orthorhombic Crystal ◽  
Metal Precursor ◽  
Ag2s Nanoparticles

Highly luminescent silver indium sulfide (AgInS2) nanoparticles were synthesized by dropwise injection of a sulfur precursor solution into a cationic metal precursor solution. The two-step reaction including the formation of silver sulfide (Ag2S) nanoparticles as an intermediate and their conversion to AgInS2 nanoparticles, occurred during the dropwise injection. The crystal structure of the AgInS2 nanoparticles differed according to the temperature of the metal precursor solution. Specifically, the tetragonal crystal phase was obtained at 140 °C, and the orthorhombic crystal phase was obtained at 180 °C. Furthermore, when the AgInS2 nanoparticles were coated with a gallium sulfide (GaSx) shell, the nanoparticles with both crystal phases emitted a spectrally narrow luminescence, which originated from the band-edge transition of AgInS2. Tetragonal AgInS2 exhibited narrower band-edge emission (full width at half maximum, FWHM = 32.2 nm) and higher photoluminescence (PL) quantum yield (QY) (49.2%) than those of the orthorhombic AgInS2 nanoparticles (FWHM = 37.8 nm, QY = 33.3%). Additional surface passivation by alkylphosphine resulted in higher PL QY (72.3%) with a narrow spectral shape.

Stable enhancement of near-band-edge emission of ZnO nanowires by hydrogen incorporation

2010 ◽  
Vol 21 (6) ◽  
pp. 065709 ◽  
Author(s):  
A Dev ◽  
R Niepelt ◽  
J P Richters ◽  
C Ronning ◽  
T Voss
Keyword(s):  
Zno Nanowires ◽  
Band Edge ◽  
Near Band Edge Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Hydrogen Incorporation
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