Enhanced Photodetection in Glancing Angle Deposited One-Dimensional In2O3 Nanorod Array

2021 ◽  
Vol 21 (5) ◽  
pp. 3115-3122
Author(s):  
Amitabha Nath ◽  
Rahul Raman ◽  
Laishram Robindro Singh ◽  
Mitra Barun Sarkar

Glancing angle deposition (GLAD) oriented electron beam (e-beam) evaporation process has been employed to develop 1D In2O3 nanorod array over n-Si substrate. The morphology of as-deposited In2O3 thin film (∼70 nm) and GLAD 1D In2O3 nanorod array (∼400 nm) were explored using field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and high resolution transmission electron microscopy (HRTEM) analysis. The structural analysis were perceived by high-resolution X-ray diffraction (HRXRD) and atomic force microscopy (AFM) techniques. The clampdown of ∼4.4 fold photoluminescence (PL) emission intensity was observed for In2O3 nanorod array. Metallization were done to measure the current (I)–voltage (V) characteristics for n-Si/In2O3 thin film and n-Si/In2O3 nanorod devices. The In2O3 nanorod device displayed ∼2.2 fold enhancement in current conduction at −4.6 V and an averagely ∼1.1 fold augmentation in photosensitivity were also observed. The photoresponsivity of ∼28 μA/W, maximum specific detectivity of ∼9.9×107 Jones and low NEP of ∼4.5×10−12 W/√Hz was achieved for the In2O3 nanorod-based photodetectors. The maximum ∼2.5 fold high detectivity and ∼2.4 fold low noise equivalent power (NEP) were perceived for the 1D In2O3 nanorod array detector as compared to the bare In2O3 thin film detector.

2012 ◽  
Vol 717-720 ◽  
pp. 873-876 ◽  
Author(s):  
Bui Van Pho ◽  
Shun Sadakuni ◽  
Takeshi Okamoto ◽  
Ryusuke Sagawa ◽  
Kenta Arima ◽  
...  

A novel abrasive-free planarization method “called catalyst-referred etching (CARE)” has been invented. After the CARE process, a flat and well-ordered surface is obtained as observed by atomic force microscopy (AFM). To determine the atomic structure at the topmost surface, in this study, CARE-processed surfaces of a standard commercial 2-inch n-type 4H-SiC (0001) wafer cut 8o off-axis toward the [1-100] direction were observed by high-resolution transmission electron microscopy (HRTEM). The HRTEM images showed alternating wide and narrow terraces and a single-bilayer step height. The relationship between the width of the terraces and the 4H-SiC crystal structure has been clarified.


2021 ◽  
Vol 11 ◽  
pp. 184798042110113
Author(s):  
Huda Abdullah ◽  
Seri Mastura Mustaza ◽  
Siti Khairani Bejo ◽  
Iskandar Yahya ◽  
Noorfazila Kamal ◽  
...  

Leptospirosis disease was caused by rat urine which contains the genus Leptospira bacteria. In this study, the fabrication of Pd-Fe-doped polyaniline nanocomposite thin films for the determination of the genus Leptospira bacteria thin films has been investigated. Pd-Fe-doped polyaniline nanocomposite thin films were fabricated by sol–gel spin coating method. The electrode sensors were immersed in the Leptospira solution. The resulting materials were investigated using field-emission scanning electron microscopy, atomic force microscopy, transmission electron microscopy, and current–voltage measurement. The atomic force microscopy images show the specific morphology films’ structure for Leptospira detection, whereas the field-emission scanning electron microscopy image shows the irregularity of clump nanoparticles in thin film surfaces. Transmission electron microscopy result shows that metal alloy (Fe-Pd) embedded in the polymer matrix. Current–voltage measurement with and without incubation of the thin film into Leptospira solution was done to show the relationship between concentration bacteria versus current. The result shows that polyaniline-Fe0.4-Pd0.6 nanocomposite thin film has higher sensitivity in detecting Leptospira, where it has performed with the highest percentage of the sensitivity of 16.9%. Besides that, selectivity tests were conducted to distinguish the existence of Leptospira, Pseudomonas aeruginosa, and Staphylococcus aureus bacteria. These results confirm the potentials of polyaniline metal alloys’ nanocomposite thin films to be used for Leptospira bacteria detection in water.


Author(s):  
S.R. Simmons ◽  
S.J. Eppell ◽  
R.E. Marchant ◽  
R.M. Albrecht

The atomic force microscope (AFM) has provided images at submolecular or atomic scale resolution of biological macromolecules attached to surfaces such as mica, graphite, or synthetic phospholipid membranes. Because the AFM can be operated with the sample in air, vacuum, or immersed in a liquid such as a biological buffer, it has the potential for high resolution imaging of the structure and organization of macromolecules on surfaces of cells in the hydrated or even living state. Realization of this potential would allow observation of molecular processes at the cell surface without the necessity for preparation of the sample for electron microscopy. To date, however, the AFM has yielded images of cell surfaces only at relatively low magnifications, and has not provided the atomic resolution achieved on hard, crystalline surfaces.Previously we have utilized correlative video-enhanced light microscopy, high voltage transmission electron microscopy, and low voltage, high resolution scanning electron microscopy (HRSEM)


2003 ◽  
Vol 11 (4) ◽  
pp. 3-7
Author(s):  
Stephen W. Carmichael

We are all familiar with the concept of correlating an image acquired by light microscopy (LM) with one obtained by transmission electron microscopy (TEM). This allows us to take advantage of the “wide angle” view of LM and the high resolution of TEM. Correlative microscopy has been taken to a new level by Alvin Lin and Cynthia Goh who have designed a clever device. This device allows repetitive correlative microscopy between TEM and atomic force microscopy (AFM).


Author(s):  
T. P. Nolan

Thin film magnetic media are being used as low cost, high density forms of information storage. The development of this technology requires the study, at the sub-micron level, of morphological, crystallographic, and magnetic properties, throughout the depth of the deposited films. As the microstructure becomes increasingly fine, widi grain sizes approaching 100Å, the unique characterization capabilities of transmission electron microscopy (TEM) have become indispensable to the analysis of such thin film magnetic media.Films were deposited at 225°C, on two NiP plated Al substrates, one polished, and one circumferentially textured with a mean roughness of 55Å. Three layers, a 750Å chromium underlayer, a 600Å layer of magnetic alloy of composition Co84Cr14Ta2, and a 300Å amorphous carbon overcoat were then sputter deposited using a dc magnetron system at a power of 1kW, in a chamber evacuated below 10-6 torr and filled to 12μm Ar pressure. The textured medium is presently used in industry owing to its high coercivity, Hc, and relatively low noise. One important feature is that the coercivity in the circumferential read/write direction is significandy higher than that in the radial direction.


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