Damage Induced By A Low-Biased 92-MHz Anode-Coupled Reactive Ion Etcher Using Chlorine-Nitrogen Mixed Plasmas

1996 ◽  
Vol 442 ◽  
Author(s):  
Tadashi Saitoh ◽  
Hideki Gotoh ◽  
Tetsuomi Sogawa ◽  
Hiroshi Kanbe
Keyword(s):  
Surface Recombination ◽  
Nanometer Scale ◽  
Nonradiative Recombination ◽  
Gaussian Shape ◽  
Ridge Structure ◽  
Surface Recombination Rate ◽  
Before And After ◽  
Recombination Centers ◽  
Etched Surface ◽  
Dry Etch

AbstractDry-etch damage, introduced by a low biased 92-MHz anode-coupled reactive ion etching (RIE), in MBE-grown undoped GaAs has been characterized by photoreflectance (PR) and photoluminescence (PL) measurements. PL spectra show emission peaks at 1.516 eV (excitons) and at 1.494 eV (D-A, B-A) before etching, whereas a new emission peak at around 1.488–1.490 eV appears after the RIE. The depth distribution of this new emission center, examined by PL measurements with a combination of step wet etching, has a Gaussian-shape with a l/e value of 56 nm. A very small number of nonradiative recombination centers are considered to be generated, because the integrated PL intensity including both emission peaks at 1.490 eV and at 1.516 eV is the same before and after the RIE. The surface recombination rate of the sidewall formed by the RIE is almost the same as that of the wet-etched surface. This low-damage etching has been applied to fabricate ultra-fine GaAs patterns to provide a nanometer-scale ridge structure with a cross-section 15-nm wide by 150-nm high. The low damage etching condition is also suitable for precise fabrication.

scholarly journals Origin of the surface recombination centers in ZnO nanorods arrays by X-ray photoelectron spectroscopy

2010 ◽  
Vol 256 (11) ◽  
pp. 3592-3597 ◽  
Author(s):  
L.L. Yang ◽  
Q.X. Zhao ◽  
M. Willander ◽  
X.J. Liu ◽  
M. Fahlman ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Zno Nanorods ◽  
Surface Recombination ◽  
X Ray ◽  
Recombination Centers

Intense Photoluminescence and Photoluminescence Enhancement of Silicon Nanocrystals by Ultraviolet Irradiation

2007 ◽  
Vol 31 ◽  
pp. 74-76 ◽  
Author(s):  
P.T. Huy ◽  
P.H. Duong
Keyword(s):  
Silicon Nanocrystals ◽  
Room Temperature ◽  
Laser Excitation ◽  
Uv Light ◽  
Irradiation Time ◽  
Excitation Wavelength ◽  
Nonradiative Recombination ◽  
Emission Yield ◽  
Recombination Centers ◽  
Pl Intensity

Photoluminescence (PL) from silicon nanocrystals deposited on top of silica-glass template and from silicon nanocrystals in nc_Si/SiO2 multilayer films were studied as a function of ultraviolet (UV) laser irradiation time in vacuum. Both the films exhibit intense visible PL at room temperature under laser excitation. It was found that upon prolong irradiation time using a He-Cd laser (325 nm) the PL intensity of the films was spectacularly enhanced. The process is reversible and does not happen with excitation wavelength longer than 400 nm. Upon introducing air into the measurement chamber, a rapid decrease of the PL intensity was recorded. This observation suggests that the UV light may lead to modification of nonradiative recombination centers in the films and thus improves the emission yield of silicon nanocrystals.

Nonradiative recombination centers in deep UV-wavelength AlGaN quantum wells detected by below-gap excitation light

2019 ◽  
Vol 58 (SC) ◽  
pp. SCCB37 ◽  
Author(s):  
M. Ismail Hossain ◽  
Yuri Itokazu ◽  
Shunsuke Kuwaba ◽  
Norihiko Kamata ◽  
Noritoshi Maeda ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Nonradiative Recombination ◽  
Excitation Light ◽  
Recombination Centers ◽  
Deep Uv

scholarly journals Photoluminescence Characterization of Nonradiative Recombination Centers in Light Emitting Materials by Utilizing Below-Gap Excitation: A Mini Review of Two-Wavelength Excited Photoluminescence

2015 ◽  
Vol 43 ◽  
pp. 1-9
Author(s):  
Norihiko Kamata ◽  
Abu Zafor Md. Touhidul Islam
Keyword(s):  
Quantum Wells ◽  
Electrical Contact ◽  
Intensity Change ◽  
Nonradiative Recombination ◽  
Excitation Light ◽  
Light Emitting ◽  
Recombination Centers ◽  
Pl Intensity ◽  
Trap Filling

We have developed an optical method of detecting and characterizing nonradiative recombination (NRR) centers without electrical contact. The method combines a below-gap excitation (BGE) light with a conventional above-gap excitation light in photoluminescence (PL) measurement, and discriminates the PL intensity change due to switching on and off the BGE. A quantitative analysis of the detected NRR centers became possible by utilizing the saturating tendency of the PL intensity change with increasing the BGE density due to trap filling effect. Some experimental results of AlGaAs, InGaN, and AlGaN quantum wells were shown to allocate the development and present status as well as to exemplify their interpretations.

THE EFFECTS OF INCREASING AlN MOLE FRACTION ON THE PERFORMANCE OF AlGaN ACTIVE REGIONS CONTAINING NANOMETER SCALE COMPOSITIONALLY INHOMOGENEITIES

2009 ◽  
Vol 19 (01) ◽  
pp. 69-76
Author(s):  
A.V. SAMPATH ◽  
M.L REED ◽  
C. MOE ◽  
G.A. GARRETT ◽  
E.D. READINGER ◽  
...  
Keyword(s):  
Mole Fraction ◽  
Point Defects ◽  
Flip Chip ◽  
Radiative Lifetime ◽  
Active Regions ◽  
Nanometer Scale ◽  
Nonradiative Recombination ◽  
Photoluminescence Intensity ◽  
Al Content ◽  
Order Of Magnitude

In this paper we report on the characterization of n - Al 0.51 Ga 0.49 N active regions and the fabrication of ultraviolet LEDs that contain self-assembled, nanometer-scale compositional inhomogeneities ( NCI - AlGaN ) with emission at ~290 nm. These active regions exhibit reduced integrated photoluminescence intensity and PL lifetime relative to 320 nm NCI - AlGaN active regions that have significantly lower AlN mole fraction, despite having more than an order of magnitude fewer threading dislocations, as measured by transmission electron microscopy. This behavior is attributed to nonradiative recombination associated with the presence of a larger density of point defects in the higher Al content samples. The point defects are ameliorated somewhat by the lower density of NCI AlGaN regions in the higher Al content samples, which leads to a larger concentration of carriers in the NCI and concomitant reduced radiative lifetime that may account for the high observed peak IQE (~ 25%). Prototype flip chip double heterostructure-NCI- ultraviolet light emitting diodes operating at 292 nm have been fabricated that employ a 50% NCI - AlGaN active region.

Sign in / Sign up

Export Citation Format

Share Document