Laser metrology for in-situ monitoring of roughness for diffusers for light emitting devices and laser manufacturing

2017 ◽  
Vol 29 (2) ◽  
pp. 022602 ◽  
Author(s):  
Wojtek J. Walecki ◽  
Peter S. Walecki ◽  
Eve S. Walecki ◽  
Abigail S. Walecki
Keyword(s):  
In Situ Monitoring ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Laser Manufacturing ◽  
Laser Metrology

Heteroepitaxy of GaN on Silicon: In Situ Measurements

2005 ◽  
Vol 483-485 ◽  
pp. 1051-1056
Author(s):  
A. Krost ◽  
Armin Dadgar ◽  
F. Schulze ◽  
R. Clos ◽  
K. Haberland ◽  
...  
Keyword(s):  
Low Cost ◽  
Group Iii Nitrides ◽  
In Situ Monitoring ◽  
Attractive Alternative ◽  
Light Emitting ◽  
Group Iii ◽  
Light Emitting Devices ◽  
Thermal Expansion Coefficients ◽  
Long Time

Due to the lack of GaN wafers, so far, group-III nitrides are mostly grown on sapphire or SiC substrates. Silicon offers an attractive alternative because of its low cost, large wafer area, and physical benefits such as the possibility of chemical etching, lower hardness, good thermal conductivity, and electrical conducting or isolating for light emitting devices or transistor structures, respectively. However, for a long time, a technological breakthrough of GaN-on-silicon has been thought to be impossible because of the cracking problem originating in the huge difference of the thermal expansion coefficients between GaN and silicon which leads to tensile strain and cracking of the layers when cooling down. However, in recent years, several approaches to prevent cracking and wafer bowing have been successfully applied. Nowadays, device-relevant thicknesses of crackfree group-III-nitrides can be grown on silicon. To reach this goal the most important issues were the identification of the physical origin of strains and its engineering by means of in situ monitoring during metalorganic vapor phase epitaxy.

Polarization Resolved Grazing Angle Scatterometry for In Situ Monitoring of Roughness for Silicon and Compound Solar Cells, Light Emitting Devices and other Structured Surfaces

MRS Advances ◽  
2017 ◽  
Vol 2 (53) ◽  
pp. 3129-3133
Author(s):  
Wojtek J. Walecki ◽  
Peter S. Walecki ◽  
Eve S. Walecki ◽  
Abigail S. Walecki
Keyword(s):  
Solar Cells ◽  
Grazing Angle ◽  
Stray Light ◽  
In Situ Monitoring ◽  
In Situ Characterization ◽  
Light Emitting ◽  
Structured Surfaces ◽  
Light Emitting Devices

ABSTRACTNovel metrology tool for in-situ characterization of surfaces semiconductor solar cells (both silicon and compound), and Light Emitting Device diffusers is presented. The tool measures the total integrated scattering when measuring forward, or back-reflection at very large angles of incidence. The tool is insensitive to vibrations and stray light. We discuss polarization resolved data and characterize our technique using NIST traceable standards. We discuss it’s applications to semiconductor manufacturing.

In Situ Inkjet Printing of the Perovskite Single-Crystal Array-Embedded Polydimethylsiloxane Film for Wearable Light-Emitting Devices

2020 ◽  
Vol 12 (19) ◽  
pp. 22157-22162 ◽  
Author(s):  
Zhenkun Gu ◽  
Zhandong Huang ◽  
Xiaotian Hu ◽  
Ying Wang ◽  
Lihong Li ◽  
...  
Keyword(s):  
Single Crystal ◽  
Inkjet Printing ◽  
Light Emitting ◽  
Light Emitting Devices

scholarly journals In situ synthesis of stretchable and highly stable multi-color carbon-dots/polyurethane composite films for light-emitting devices

RSC Advances ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 1281-1286 ◽  
Author(s):  
Fei Lian ◽  
Chuanxi Wang ◽  
Qian Wu ◽  
Minghui Yang ◽  
Zhenyu Wang ◽  
...  
Keyword(s):  
Polymer Films ◽  
Carbon Dots ◽  
Composite Films ◽  
Optoelectronic Devices ◽  
In Situ Synthesis ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Polyurethane Composite

Stretchable, mechanically stable multi-color carbon-dots-based polymer films are in situ fabricated, and showed potential for application in optoelectronic devices.

Investigations on the Aluminum/Para-Hexaphenyl Interface in Light Emitting Devices

1997 ◽  
Vol 488 ◽  
Author(s):  
N. Koch ◽  
L.-M. Yu ◽  
J.-L. Guyaux ◽  
Y. Morciaux ◽  
G. Leising ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Active Material ◽  
Direct Interaction ◽  
Metal Electrode ◽  
Insulating Layer ◽  
Aluminum Films ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Thin Aluminum

AbstractBlue light emitting devices (LED) with para-hexaphenyl (PHP) as the active material and aluminum as cathode exhibit very high quantum efficiencies. To further optimize device performance it is crucial to understand the physical properties of the involved interfaces. We have performed Rutherford-Backscattering experiments on actual devices to show the importance of oxygen in the interface formation at the cathode as this leads to the formation of a layer of AlxOy between PHP and aluminum. In devices, where the organic film is exposed to air before the metal electrode is evaporated, an insulating layer on the metal-side therefore is inherent. It has been shown that the introduction of an intermediate layer between active material and electrodes results in a higher quantum efficiency of the LED, the most common concepts being charge-transport-layers, or insulators on the other hand. Our results underline the need for a better control of the LED processing. Ultraviolet- and X-ray photoelectron spectroscopy in situ growth studies of thin aluminum films on PHP have been made to reveal the change in the electronic structure of the active medium in a LED in the absence of oxygen. Also the direct interaction of oxygen with this organic material is investigated by photoelectron spectroscopy.

Ionic liquid-induced in-situ deposition of perovskite quantum dot films with photoluminescence quantum yield over 85%

Nanoscale ◽  
2021 ◽  
Author(s):  
Qiugui Zeng ◽  
Xin Luo ◽  
Yiying Du ◽  
Jiexuan Jiang ◽  
Lin Yang ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Building Blocks ◽  
Great Promise ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Photoluminescence Quantum Yield ◽  
In Situ Deposition ◽  
Metal Halide Perovskite ◽  
Perovskite Quantum Dots

Metal halide perovskite quantum dots (QDs) hold great promise as building blocks for next-generation light emitting devices (LEDs). The preparation of perovskite QD films with high photoluminescence quantum yield (PLQY)...

scholarly journals Microwave-assisted in situ large scale synthesis of a carbon dots@g-C3N4 composite phosphor for white light-emitting devices

2020 ◽  
Vol 4 (2) ◽  
pp. 517-523 ◽  
Author(s):  
Li Meng ◽  
Elena V. Ushakova ◽  
Zhengjie Zhou ◽  
Enshan Liu ◽  
Di Li ◽  
...  
Keyword(s):  
White Light ◽  
Carbon Dots ◽  
Power Efficiency ◽  
Large Scale ◽  
Heating Method ◽  
Light Emitting ◽  
White Leds ◽  
Light Emitting Devices ◽  
Microwave Assisted

A composite phosphor comprising carbon dots and g-C3N4 is prepared on a large scale through a green microwave assisted in situ heating method, and is used for fabrication of white LEDs with a power efficiency of up to 42 lm W−1.

Polymer-Assisted In Situ Growth of All-Inorganic Perovskite Nanocrystal Film for Efficient and Stable Pure-Red Light-Emitting Devices

2018 ◽  
Vol 10 (49) ◽  
pp. 42564-42572 ◽  
Author(s):  
Wanqing Cai ◽  
Ziming Chen ◽  
Zhenchao Li ◽  
Lei Yan ◽  
Donglian Zhang ◽  
...  
Keyword(s):  
Red Light ◽  
In Situ Growth ◽  
Light Emitting ◽  
Inorganic Perovskite ◽  
Light Emitting Devices
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