scholarly journals Development of Cost-Effective Native Substrates for Gallium Nitride-Based Optoelectronic Devices via Ammonothermal Growth

Author(s):  
Tadao Hashimoto ◽  
Edward Letts
Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1641 ◽  
Author(s):  
Maksym Stetsenko ◽  
Salvatore A. Pullano ◽  
Tetiana Margitych ◽  
Lidia Maksimenko ◽  
Ali Hassan ◽  
...  

A straightforward and effective spin-coating technique at 120 °C was investigated for the deposition of a thin nanoporous layer with antireflection properties onto glass and indium tin oxide (ITO) coated glass. A mixture of zeolite 3A powder and high iodine value vegetable oil was deposited, creating a carbonic paste with embedded nanoporous grains. Experimental results evidenced excellent broadband antireflection over the visible-near-infrared wavelength range (450–850 nm), with a diffuse reflectance value of 1.67% and 1.79%. Structural and optical characteristics stabilized over time. The results are promising for the accessible and cost-effective fabrication of an antireflective surface for optoelectronic devices.


2018 ◽  
Vol 20 (37) ◽  
pp. 24239-24249 ◽  
Author(s):  
Ying Guo ◽  
Feng Pan ◽  
Yajie Ren ◽  
Binbin Yao ◽  
Chuanghua Yang ◽  
...  

Recently, two-dimensional (2D) gallium nitride (GaN) was experimentally fabricated, and has promising applications in next-generation electronic and optoelectronic devices.


2004 ◽  
Vol 19 (6) ◽  
pp. 1768-1774 ◽  
Author(s):  
A. Chatterjee ◽  
S. Chattopadhyay ◽  
C.W. Hsu ◽  
C.H. Shen ◽  
L.C. Chen ◽  
...  

Sol-gel derived catalyst systems of cobalt, nickel, and iron were used in the growth of gallium nitride (GaN) nanowires by thermal chemical vapor deposition. A diffusion barrier matrix of titania (TiO2) has been used in which the catalysts were dispersed to have control of the catalyst particle sizes and hence on the size and morphology of the GaN nanowires. This single-step and cost-effective processing of the catalyst bed produced good-quality GaN naowires with comparable structural and optical properties with those previously reported. In a particular case, a stress-induced cubic admixture to the otherwise hexagonal structural symmetry was observed. The samples were characterized by high-resolution scanning electron microscopy, x-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and cathodo-luminescence studies.


2012 ◽  
Vol 1415 ◽  
Author(s):  
J. Justice ◽  
L. E. Rodak ◽  
K. Lee ◽  
L. A. Hornak ◽  
D. Korakakis

ABSTRACTGallium nitride (GaN) is a robust piezoelectric semiconductor with excellent thermal and chemical stability, making it an attractive material for surface acoustic wave (SAW) sensors operating in high temperature and harsh environments. The sensitivity of SAW devices is proportional to the square of the operating frequency. Therefore, high operating frequencies into the GHz regime are desirable for SAW sensors. For GaN, this requires sub-micron interdigital transducers (IDTs) when devices are designed to operate at the fundamental Rayleigh mode frequency. The necessity for sub-micron IDTs can increase fabrication costs and complexity. By designing SAW devices to operate at harmonic frequencies, GHz operation can be realized with relatively large IDTs, resulting in simpler and more cost effective solutions for GaN based SAW sensors. Devices have previously been designed to operate at the 5th and higher harmonics on lithium niobate, but there are no reports of using this technique on GaN in the literature. In this study, GaN thin films have been grown via metal organic vapor phase epitaxy on sapphire substrates. SAW devices designed to operate at the fundamental frequency and higher harmonics have been fabricated and measured. Operating frequencies greater than 2 GHz have been achieved using IDTs with 5 μm fingers. In addition, reduction of electromagnetic feedthrough around the 5th and 7th harmonic is demonstrated through varying ground electrode geometries.


2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Rohit Saraf ◽  
Hua Fan ◽  
Vivek Maheshwari

AbstractFlexible, large-area, and stable perovskite photodetectors have drawn increasing widespread research attention for next-generation wearable and portable optoelectronic devices. However, high mechanical durability coupled with large device area and enhanced environmental stability has not been demonstrated yet to attain practical viability. Herein, a highly bendable, stable, and large-area (3 cm2) flexible polystyrene incorporated perovskite photodetector is presented. Due to the formation of a porous polystyrene-perovskite composite film in a single step it allows unprecedented mechanical stability, maintaining 85% of its original photocurrent value after 10,000 bending cycles at a bending angle of 120°. Equally crucial, the solution-processed self-assembled Pt–Au nanochains were developed to provide a simple and fast method of patterning the conductive and flexible electrodes onto the filter substrate. The optimized polystyrene-perovskite photodetector exhibits a high responsivity up to 2.73 A W−1, a maximum specific detectivity of 6.2 × 1013 Jones, and a superior switching ratio of 1.0 × 104. In addition, the polystyrene-perovskite photodetector yields excellent stability under the combined stresses of moisture, ambient air, and room light, and retains 92% of its original performance for over 30 days. All these results demonstrate that this work provides a facile and cost-effective approach that paves the way to develop high-performance, stable, and highly flexible optoelectronic devices.


2014 ◽  
Vol 59 (12) ◽  
pp. 1087-1093
Author(s):  
Kun XU ◽  
Xin LIU ◽  
WeiLing GUO ◽  
Jie SUN ◽  
Chen XU

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Qinghua Wang ◽  
Haoxuan You ◽  
Zach Lowery ◽  
Songwei Li ◽  
Hao Fu ◽  
...  

Abstract Flexible optoelectronic devices have attracted considerable attention due to their low weight, portability, and ease of integration with other devices. However, major issues still exist: they are subject to repeated stresses, which often leads to damage; and the current fabrication methods such as photolithography and nano-imprint lithography can be very time-consuming or costly. This work aims to develop a novel cost-effective and time-efficient laser metasurface fabrication (LMF) technique for production of flexible optoelectronic devices. The experimental results have shown that the laser patterned flexible surfaces exhibit high visible transmittance, low sheet resistance, and extraordinary mechanical durability under repeated bending cycles. The laser patterned flexible surfaces have also demonstrated the potential to be utilized as heaters, which renders them new de-icing or de-fogging applications. This innovative laser patterning method will provide a new avenue for fabrication of multifunctional optoelectronic devices.


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