Characterization of low-frequency noise in molecular beam epitaxy-grown GaN epilayers deposited on double buffer layers

Author name used in this publication: W. K. FongAuthor name used in this publication: S. W. NgAuthor name used in this publication: B. H. Leung2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Program Komputer RPG Matematika Aljabar

Game edukasi matematika berjenis RPG dibuat untuk membantu siswa kelas 7 SMP dalam mempelajari dan meningkatkan motivasi mereka terhadap aljabar. Game RPG ini dibuat menggunakan RPG Maker MV

A Novel Cryo-controlled Growth Technique for High Performance Organometal Halide Perovskite Solar Cells

The recent trend of the high-performance perovskite solar cell (PSC) is based on multi-component perovskite materials. The reproducible perovskite growth techniques are crucial for acquiring mixed halide perovskite films with precise stoichiometry, desirable morphology, and low defect density

Nitrogen doped-ZnO/n-GaN heterojunctions

Nitrogen-doped ZnO nanorods were prepared by electrodeposition using two different Zn precursors (zinc nitrate and zinc acetate), while all other growth conditions (dopant precursor, concentration, growth temperature, and bias) were identical. We have shown that the precursor used affects the properties of the ZnO nanorods, and that the presence of rectifying properties in n-GaN/N:ZnO heterojunctions is strongly related to the use of nitrate precursor for ZnO growth. The difference in the properties of ZnO obtained from two precursors is attributed to the differences in native defect and impurity concentrations, which could affect the electronic properties of the samples. © 2011 American Institute of Physics.published_or_final_versio

ZnO nanorod/GaN light-emitting diodes: The origin of yellow and violet emission bands under reverse and forward bias

ZnO nanorods have been prepared by electrodeposition under identical conditions on various p-GaN-based thin film structures. The devices exhibited lighting up under both forward and reverse biases, but the turn-on voltage and the emission color were strongly dependent on the p-GaN-based structure used. The origin of different luminescence peaks under forward and reverse bias has been studied by comparing the devices with and without ZnO and by photoluminescence and cathodoluminescence spectroscopy. We found that both yellow-orange emission under reverse bias and violet emission under forward bias, which are commonly attributed to ZnO, actually originate from the p-GaN substrate and/or surface/interface defects. While the absolute brightness of devices without InGaN multiple quantum wells was low, high brightness with luminance exceeding 10 000 cd/m 2 and tunable emission (from orange at 2.1 V to blue at 2.7 V, with nearly white emission with Commission internationale de l'éclairage (CIE) coordinates (0.30, 0.31) achieved at 2.5 V) was obtained for different devices containing InGaN multiple quantum wells. © 2011 American Institute of Physics.published_or_final_versio

Solution-based growth of ZnO nanorods for light-emitting devices: Hydrothermal vs. electrodeposition

ZnO nanorods have been grown by two inexpensive, solution-based, low-temperature methods: hydrothermal growth and electrodeposition. Heterojunction n-ZnO nanorods/p-GaN light-emitting diodes have been studied for different nanorod growth methods and different preparation of the seed layer. We demonstrate that both the nanorod properties and the device performance are strongly dependent on the growth method and seed layer. All the devices exhibit light emission under both forward and reverse bias, and the emission spectra can be tuned by ZnO nanorod deposition conditions. Electrodeposition of rods or a seed layer results in yellow emission, while conventional hydrothermal growth results in violet emission. © The Author(s) 2010. This article is published with open access at Springerlink.com.published_or_final_versionSpringer Open Choice, 01 Dec 201

Limitation in fabricating PSf/ZIF-8 hollow fiber membrane for CO2/CH4 separation

Hollow fiber membrane configuration is way forward in membrane development since it possesses higher packing density and effective surface area per unit module compared to other configuration. Since majority of mixed matrix membrane (MMM) for gas separation reported focuses on flat sheet membrane development, this report aims to address the challenges faced in fabricating hollow fiber MMM. In this study, hollow fiber formulation is fabricated and their MMM using different types of fillers (virgin and modified ZIF-8) are prepared and used as a dispersed phase. The neat hollow fiber membrane shows good results with CO2 permeance of 104.39 GPU and CO2/CH4 selectivity of 29.28, in comparison with reported literature. Upon filler incorporation, the resulted MMMs appear to be diminished in both CO2 permeance and CO2/CH4 selectivity. While using modified ZIF-8, lesser deterioration was shown compared to pure ZIF-8, this phenomenon is likely to occur due to the changes in solution stability which causes notable changes in membrane morphology and performances

Perbandingan Algoritma C4.5 dan Classification and Regression Tree (CART) Dalam Menyeleksi Calon Karyawan

This research compares the accuracy of the C4.5 algorithm and Classification and Regression Tree (CART) for prospective employees selection in companies. This research using dataset with criteria like age, working experience, recent education, marital status, number of abilities possessed, and the result of admission selection test. Testing uses 200 prospective employee selection data manually from a company. Algorithm testing using K-Fold Cross Validation and the accuracy calculation of the algorithm using Confusion Matrix. C4.5 algorithm has a level of accuracy, the success rate of the system, and the level of accuracy of the decision results of 52,83%, 41,48% and 43,98%, and CART algorithm is 53,33%, 44,06%, and 42,81%