Film Preparation Conditions and Characterization of co-Deposited Tungsten Doped Zinc Oxide Phosphor

1999 ◽  
Vol 558 ◽  
Author(s):  
Jasleen Bombra Sobti ◽  
V. Bhatia ◽  
P. M. Babuchna ◽  
Mark H. Weichold

ABSTRACTNeed for efficient blue light emitting source for optoelectronic device applications such as flat panel displays has made the research in luminescent material ever so important. Tungsten doped zinc oxide (ZnO:W) has been identified as a blue light emitting phosphor exhibiting cathodoluminescence near 490 nm. This paper details work done on ZnO:W phosphor preparation conditions for efficient light emission from the phosphor. Material characterization to identify the possible source of blue light emission will also be discussed.

1999 ◽  
Vol 560 ◽  
Author(s):  
Jasleen Bombra Sobti ◽  
V. Bhatia ◽  
P. M. Babuchna ◽  
Mark H. Weichold

ABSTRACTNeed for efficient blue light emitting source for optoelectronic device applications such as flat panel displays has made the research in luminescent material ever so important. Tungsten doped zinc oxide (ZnO:W) has been identified as a blue light emitting phosphor exhibiting cathodoluminescence near 490 tim. This paper details work done on ZnO:W phosphor preparation conditions for efficient light emission from the phosphor. Material characterization to identify the possible source of blue light emission will also be discussed.


1994 ◽  
Vol 08 (02) ◽  
pp. 69-92 ◽  
Author(s):  
XUN WANG

In this review article, we give a new insight into the luminescence mechanism of porous silicon. First, we observed a “pinning” characteristic of photoluminescent peaks for as-etched porous silicon samples. It was explained as resulting from the discontinuous variation of the size of Si nanostructures, i.e. the size quantization. A tight-binding calculation of the energy band gap widening versus the dimension of nanoscale Si based on the closed-shell Si cluster model agrees well with the experimental observations. Second, the blue-light emission from porous silicon was achieved by using boiling water treatment. By investigating the luminescence micrographic images and the decaying behaviors of PL spectra, it has been shown that the blue-light emission is believed to be originated from the porous silicon skeleton rather than the surface contaminations. The conditions for achieving blue light need proper size of Si nanostructures, low-surface recombination velocity, and mechanically strong skeleton. The fulfillment of these conditions simultaneously is possible but rather critical. Third, the exciton dynamics in light-emitting porous silicon is studied by using the temperature-dependent and picosecond time-resolved luminescence spectroscopy. A direct evidence of the existence of confined excitons induced by the quantum size effect has been revealed. Two excitation states are found to be responsible for the visible light emission, i.e. a higher lying energy state corresponding to the confined excitons in Si nanostructures and a lower lying state related with surfaces of Si wires or dots. A picture of the carrier transfer between the quantum confined state and the surface localized state has been proposed. Finally, we investigated the transient electroluminescence behaviors of Au/porous silicon/Si/Al structure and found it is very similar to that of an ordinary p-n junction light-emitting diode. The mechanism of electroluminescence is explained as the carrier injection through the Au/porous silicon Schotky barrier and the porous silicon/p-Si heterojunction into the corrugated Si wires, where the radiative recombination of carriers occurs.


2011 ◽  
Vol 19 (23) ◽  
pp. 23429 ◽  
Author(s):  
Young Jae Park ◽  
Ji Hye Kang ◽  
Hee Yun Kim ◽  
Volodymyr V. Lysak ◽  
S. Chandramohan ◽  
...  

2015 ◽  
Vol 5 (6) ◽  
pp. 1331 ◽  
Author(s):  
Jian Sun ◽  
Jianmei Xu ◽  
Xiaosheng Tang ◽  
Yanhua Huang ◽  
Chunhua Tang ◽  
...  

1999 ◽  
Vol 588 ◽  
Author(s):  
Xingsheng Liu ◽  
Jesus Noel Calata ◽  
Houyun Liang ◽  
Wangzhou Shi ◽  
Xuanyin Lin ◽  
...  

AbstractThrough a comparative study of the light emission and light excitation property of porous silicon (PS) and Si oxide, photoluminescence (PL) and photoluminescence excitation (PLE) mechanisms for blue-light-emitting PS are analyzed. Strong blue light (445nm) and ultraviolet light (365nm) emission from silicon-rich silicon oxynitride films at room temperature were observed. An analysis of the PL and PLE spectra of PS and Si oxide indicated that for blue-light emission from PS, there are two types of photoexcitation processes: photo-excitation occurring in nanometer Si particles (NSP's) and in the Si oxide layers covering NSPs, and radiative recombination of electron-hole pairs taking place in luminescence centers (LCs) located on the interfaces between NSP's and Si oxide and those inside Si oxide layers. The PL spectra of silicon-rich silicon oxynitride films implies that the PL originated from some LCs in SiOx and SiOxNy:H, while PLE spectra indicates that photoexcitation occurs in NSPs, SiOx and SiOxNy:H. The 365 nm band is attributed to the former two photoexcitation processes and the 445 nm one to the third process. As such, the quantum confinement/luminescence center model appears to be a satisfactory model in explaining the experimental results.


2021 ◽  
Author(s):  
Muhammad Aamir Iqbal ◽  
Maria Malik ◽  
Wajeehah Shahid ◽  
Waqas Ahmad ◽  
Kossi A. A. Min-Dianey ◽  
...  

Plasmonics is a technologically advanced term in condensed matter physics that describes surface plasmon resonance where surface plasmons are collective electron oscillations confined at the dielectric-metal interface and these collective excitations exhibit profound plasmonic properties in conjunction with light interaction. Surface plasmons are based on nanomaterials and their structures; therefore, semiconductors, metals, and two-dimensional (2D) nanomaterials exhibit distinct plasmonic effects due to unique confinements. Recent technical breakthroughs in characterization and material manufacturing of two-dimensional ultra-thin materials have piqued the interest of the materials industry because of their extraordinary plasmonic enhanced characteristics. The 2D plasmonic materials have great potential for photonic and optoelectronic device applications owing to their ultra-thin and strong light-emission characteristics, such as; photovoltaics, transparent electrodes, and photodetectors. Also, the light-driven reactions of 2D plasmonic materials are environmentally benign and climate-friendly for future energy generations which makes them extremely appealing for energy applications. This chapter is aimed to cover recent advances in plasmonic 2D materials (graphene, graphene oxides, hexagonal boron nitride, pnictogens, MXenes, metal oxides, and non-metals) as well as their potential for applied applications, and is divided into several sections to elaborate recent theoretical and experimental developments along with potential in photonics and energy storage industries.


2013 ◽  
Vol 1538 ◽  
pp. 371-375
Author(s):  
Zhao Si ◽  
Tongbo Wei ◽  
Jun Ma ◽  
Ning Zhang ◽  
Zhe Liu ◽  
...  

ABSTRACTA study about the achievement of dichromatic white light-emitting diodes (LEDs) was performed. A series of dual wavelength LEDs with different last quantum-well (LQW) structure were fabricated. The bottom seven blue light QWs (close to n-GaN layer) of the four samples were the same. The LQW of sample A was 3 nm, and that of sample B, C and D were 6 nm, a special high In content ultra-thin layer was inserted in the middle of the LQW of sample C and on top of that of sample D. XRD results showed In concentration fluctuation and good interface quality of the four samples. PL measurements showed dual wavelength emitting, the blue light peak position of the four samples were almost the same, sample A with a narrower LQW showed an emission wavelength much shorter than that of sample B, C, D. EL measurement was done at an injection current of 100 mA. Sample A only showed LQW emission due to holes distribution. Because of wider LQW, the emission wavelength of sample B, C and D was longer and peak intensity was weaker. Sample D with insert layer on top of LQW showed strongest yellow light emission with a blue peak. As the injection current increased, sample A showed highest output light power due to narrower LQW. Of the other three samples with wider LQW, sample D showed highest output power. Effective yellow light emission has always been an obstacle to the achievement of dichromatic white LED. Sample D with insert layer close to p-GaN can confine the hole distribution more effectively hence the recombination of holes and electrons was enhanced, the yellow light emission was improved and dichromatic white LED was achieved.


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