Editor, Author at Institute of Nano Electronic Engineering

Effect of different solvents on the structural and optical properties of zinc oxide thin films for optoelectronic applications

January 2, 2015 By Editor

Abstract – Zinc oxide (ZnO) seed solutions were prepared using 4 different solvents, namely, methanol (MeOH), ethanol (EtOH), isopropyl alcohol (IPA) and 2-methoxyethanol (2-ME). The prepared seed solutions were used to synthesize ZnO thin films using a low-cost sol–gel spin-coating method. The effect of different solvents on the structural and optical properties of ZnO thin films was investigated by field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and an ultraviolet–visible–near infrared spectrophotometer (UV–vis–NIR). The images obtained in the FESEM and AFM showed that the thin film prepared using 2-ME has the smallest grain size. Moreover, the X-ray diffraction (XRD) results showed that the synthesized ZnO films are polycrystalline with preferred orientation along the (002) plane, whereas the IPA- derived films have a preferred orientation on (101) plane. The ZnO thin film synthesized with 2-ME has the highest transmittance (>90%), lowest surface roughness of 3.131 nm and highest band gap energy of 3.28 eV. The experimental data are in agreement with the calculated results by specific models of refractive index.

Keywords – Zinc oxide, Solvents, Optical, Structural, Sol–gel

Corresponding Author: Foo Kai Loong
Corresponding Author’s Email: klfoo@unimap.edu.my

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On the MOSFET Threshold Voltage Extraction by Transconductance and Transconductance-to-Current Ratio Change Methods: Part II-Effect of Drain Voltage

January 2, 2015 By Editor

Abstract – In this paper, we study the effect of the drain voltage on the threshold voltage extraction in long-channel MOSFETs by the transconductance change and transconductance-to-current ratio change methods, using analytical modeling and experimental data obtained on advanced UTB SOI MOSFETs. It is shown that, although these two methods have the same physical background, they feature radically different behaviors with respect to the drain voltage effect. In particular, the transconductance change method yields a threshold voltage value, which regularly increases with drain voltage, and interpretation, as well as analytical expression for this dependence, is provided. In contrast, for the transconductance-to-current ratio change method, the increase of the extracted threshold voltage value with drain voltage is smaller and rapidly saturates; hence, the threshold voltage extraction is more stable and reliable. Modeling derivations are found to be in excellent agreement withmeasurements on long-channel UTB SOI MOSFETs as well as 2-D simulations.

Keywords – MOSFET threshold voltage extraction, transconductance change method, transconductance-to-current ratio, unified charge control model (UCCM).

Corresponding Author: Mohd Khairuddin Md Arshad
Corresponding Author’s Email: mohd.khairuddin@unimap.edu.my

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Synthesis and characterization of graphene and carbon nanotubes: A review on the past and recent developments

December 24, 2014 By Editor

Abstract – Carbon nanotubes (CNTs) and graphene have built broad interest in most areas of science and engineering because of their extraordinary physical, mechanical, thermal and optical properties. Graphene is a two-dimensional one-atom-thick planar sheet of sp2-bonded carbon atoms while CNTs are a cylindrical nanostructure which composed entirely of sp2-bonded carbon atoms as well. This review presents and discusses the past and current advancement of synthesis and characterization of graphene and CNTs. The review also concludes with a brief summary and an outlook on the challenges and future
prospects in the growth of graphene and CNTs.

Keywords – carbon nanotubes, cnt, graphene oxide, reduced graphene oxide

Corresponding Author: Liu Wei Wen
Corresponding Author’s Email: wwliu@unimap.edu.my

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Sol–gel synthesis of Pd doped ZnO nanorods for room temperature hydrogen sensing applications

December 23, 2014 By Editor

Abstract – A sol-gel spin coating technique was described for the synthesis of Pd doped ZnO nanorods for hydrogen sensing applications. The nanorods were hexagonal in shape, 50–100 nm in diameter and uniform in distribution. They exhibited homogeneous surface morphology, c-axis orientation and excellent crystalline properties. The synthesized nanorods were used to sense and detect hydrogen in a homemade gas chamber. The fabricated sensor successfully detected as low as 40 ppm hydrogen at room temperature with a very low level of power supply (16.16 mA) under a mixed background. Dynamic and repeated responses were observed with a wide range of hydrogen concentrations (40–360 ppm) at 200 C. The developed sensor was at least 25 fold more sensitive over the literature documented Pd doped ZnO nanorods in detecting hydrogen at ambient temperature. The simplicity, low-cost, high sensitivity and high stability of the sensor materials suggested that the synthesized Pd doped ZnO nanorods could be used in hydrogen and chemical sensing devices where Pd-mediated catalysis is involved.

Keywords – Pd doped ZnO nanorods, Hydrogen sensors, Sol–gel, Spin coating

Corresponding Author: Uda Hashim
Corresponding Author’s Email: uda@unimap.edu.my

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Prof. Dr. Uda Hashim memenangi anugerah tertinggi di BioInnovation Awards 2014

November 24, 2014 By Editor

Universiti Malaysia Perlis (UniMAP) terus mengungguli bidang penyelidikan negara dengan meraih anugerah khas tertinggi, Biotechnology Innovation Of The Year pada BioInnovation Awards 2014 yang diadakan di Pusat Konvensyen Kuala Lumpur (KLCC).

BioInnovation Awards 2014
Anugerah diperolehi menerusi produk Nano DNA Chips for Early Detection of Cervical Cancer oleh Prof. Dr. Uda Hashim dari Institut Kejuruteraan Nano Electronik (INEE) yang melayakkan beliau menerima wang tunai RM 4000, trofi dan sijil penyertaan.

Menurut Prof. Dr. Uda Hashim, beliau sama sekali tidak percaya akan meraih anugerah tertinggi tersebut selain turut mendapat pingat emas dalam pameran tersebut.

“Saya amat bersyukur kerana mencapai sasaran bagi mendapat pingat emas tetapi saya sama sekali tidak menyangka akan memperolehi anugerah tertinggi ini.

“Ini merupakan satu penghargaan yang besar buat saya dan anugerah ini menjadi penutup penyertaan saya dalam pameran penyelidikan peringkat kebangsaan bagi tahun ini,” katanya.

Tambahnya lagi, penyertaan beliau dalam pameran ini bukan semata-mata menyasarkan kutipan pingat sebaliknya beliau mahukan produk tersebut menjadi sebagai salah satu sumbangan bagi membantu masyarakat dan pengamal perubatan dalam pengesanan penyakit kanser pada peringkat awal.

Selain Prof. Uda, UniMAP turut meraih anugerah khas bagi kategori Most Promising Innovation menerusi produk Large – Scale Naturally Ventilated Tropical Greenhouse Structure For Commercial Harumanis Production in Perlis oleh Prof. IR. Dr. Rezuwan Kamaruddin dari Institut Agroteknologi dan seterusnya membawa pulang wang tunai RM 2000, trofi dan sijil penyertaan.

Malah produk yang sama juga turut menjadi penyumbang emas kedua UniMAP.

Pada penyertaan kali ini, UniMAP turut meraih empat perak dan lapan gangsa serta tempat ketiga pertandingan rekaan booth bagi kategori Bare Space.

Naib Canselor UniMAP, Brig. Jeneral Datuk Prof. Dr. Kamarudin Hussin berkata, pameran ini adalah pameran yang sengit di mana cara penjuriannya adalah lebih tegas dan terperinci.

“Produk yang kita pilih untuk mewakili UniMAP adalah produk-produk yang terbaik tetapi mungkin faktor pengalaman yang memisahkan mereka dengan kejayaan. Kebanyakan penyelidik UniMAP kali ini merupakan penyelidik yang baharu pertama kali menyertai pameran sebegini.

“Namun pemilihan mereka adalah berdasarkan kualiti produk yang dihasilkan dan saya percaya mereka telah mendapat pendedahan yang secukupnya sebagai persediaan bagi pameran yang lebih besar pada tahun hadapan,” katanya ketika dihubungi selepas keputusan pameran itu diumumkan.

BioInnovation Awards 2014 dianjurkan bersama dengan Biotechnology Asia oleh Malaysian Association of Research Scientist 2014 (MARS) dan Professional Trade Exhibition and Meeting Planners (PROTEMP) bermula 19 hingga 21 November 2014.

Sumber: Laman Web Rasmi UniMAP