{"id":77,"date":"2017-12-20T15:20:07","date_gmt":"2017-12-20T15:20:07","guid":{"rendered":"http:\/\/www.ee.uconn.edu\/anwar-research\/?page_id=77"},"modified":"2018-10-24T16:01:41","modified_gmt":"2018-10-24T16:01:41","slug":"zno","status":"publish","type":"page","link":"https:\/\/www.ee.uconn.edu\/anwar-research\/zno\/","title":{"rendered":"ZnO"},"content":{"rendered":"<div id=\"pl-77\"  class=\"panel-layout\" ><div id=\"pg-77-0\"  class=\"panel-grid panel-no-style\" ><div id=\"pgc-77-0-0\"  class=\"panel-grid-cell\" ><div id=\"panel-77-0-0-0\" class=\"so-panel widget widget_nav_menu panel-first-child panel-last-child\" data-index=\"0\" ><h3 class=\"widget-title\">Research Topics<\/h3><div class=\"menu-research-menu-container\"><ul id=\"menu-research-menu\" class=\"menu\"><li id=\"menu-item-282\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-282\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/memristor\/\">Memristor<\/a><\/li>\n<li id=\"menu-item-291\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-291\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/zno\/\">ZnO<\/a><\/li>\n<li id=\"menu-item-283\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-283\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/thz\/\">THz<\/a><\/li>\n<li id=\"menu-item-284\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-284\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/quantum-cascade-laser\/\">Quantum Cascade Laser<\/a><\/li>\n<li id=\"menu-item-285\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-285\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/high-electron-mobility-transistors-hemts\/\">High Electron Mobility Transistors (HEMTs)<\/a><\/li>\n<li id=\"menu-item-286\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-286\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/heterojunction-bipolar-transistors-hbts\/\">Heterojunction Bipolar Transistors (HBTs)<\/a><\/li>\n<li id=\"menu-item-287\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-287\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/resonant-tunneling-devices\/\">Resonant Tunneling Devices<\/a><\/li>\n<li id=\"menu-item-288\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-288\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/transport-in-semiconductors\/\">Transport in Semiconductors<\/a><\/li>\n<li id=\"menu-item-289\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-289\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/noise-in-semiconductor-devices\/\">Noise in Semiconductor Devices<\/a><\/li>\n<li id=\"menu-item-290\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-290\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/thz-assisted-counterfeit-detection\/\">THz Assisted Counterfeit Detection<\/a><\/li>\n<li id=\"menu-item-292\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-292\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/engineered-nanostructures-for-authentication\/\">Engineered Nanostructures for Authentication<\/a><\/li>\n<li id=\"menu-item-305\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-305\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/solar-blind-detector\/\">Solar Blind Detector<\/a><\/li>\n<li id=\"menu-item-381\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-381\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/photonics\/\">Photonics<\/a><\/li>\n<li id=\"menu-item-382\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-382\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/si-related-devices\/\">Si &amp; Related Devices<\/a><\/li>\n<li id=\"menu-item-383\" class=\"menu-item menu-item-type-post_type menu-item-object-page menu-item-383\"><a href=\"https:\/\/www.ee.uconn.edu\/anwar-research\/fundamental-physics\/\">Fundamental Physics<\/a><\/li>\n<\/ul><\/div><\/div><\/div><div id=\"pgc-77-0-1\"  class=\"panel-grid-cell\" ><div id=\"panel-77-0-1-0\" class=\"so-panel widget widget_sow-editor panel-first-child panel-last-child\" data-index=\"1\" ><div\n\t\t\t\n\t\t\tclass=\"so-widget-sow-editor so-widget-sow-editor-base\"\n\t\t\t\n\t\t>\n<div class=\"siteorigin-widget-tinymce textwidget\">\n\t<p><span style=\"font-size: 24pt;\"><strong>Zinc Oxide<\/strong><\/span> is a wide band gap semiconductor with a relatively large exciton energy of 60\u202fmeV, and longitudinal optical phonon energy of 72\u202fmeV. ZnO can be grown in any nanostructure such as nanoribbons, nanowires, nanorods, films, core-shell, among others, to be implemented in a variety of applications improving the current state of the art. In our group, we have grown under metal-organic chemical vapor deposition (MOCVD), films, nanowires, nanorods and heterostructures with extraordinary crystal and optical quality. For instance, by adding Mg to ZnO, the energy band separation increases and shift to a lower wavelength. We have pushed the ZnO energy band gap to 4.17 eV by adding up to 30% of Mg, which makes it suitable for UV detection\/laser. In addition to the optoelectronic applications, we have also used ZnMgO to growth ZnMgO\/ZnO co-axial core-shell structures enhancing the gas sensing properties by inducing native defects at the ZnMgO-ZnO junction. As the lattice mismatch increase upon Mg mole fraction, for a core less than the critical layer, native defects raise from the built in-strain. The native defects work as donors that are released upon in contact with the gas.<\/p>\n<p>At lower temperature, we have used hydrothermal synthesis to growth ZnO nanorods (NRs) in p-Si, SiO2, GaN and a flexible substrate. The flexible substrate is of high interest as it brings down cost and provides a platform for different application, especially when it comes to energy harvesting. For this matter, we fabricated a device using two flexible substrates with the NR sides facing each. As ZnO is a piezoelectric material, meaning that it can convert mechanical vibration into an electric potential, using a load of 0.17 kg\/cm2 the device produced a maximum open-circuit voltage of 1.4 V (peak). The output voltage can be used to self-powered sensors such as gas and vibrations. It can also be used to recover energy from noisy environments.<\/p>\n<p>The growth of vertically aligned nanorods at low temperature is very straightforward. However, when it comes to horizontally aligned nanowires (NWs) most reported horizontal NWs\/NRs are grown by confining the growth along the surface using patterns, dislocations, and catalyst. A novel process has been developed by our group to grow horizontal nanowires using controlled hydrothermal synthesis. It is to be noted that unlike the standard practice of growing vertical NRs followed by pick-and-place technique to obtain horizontal nanostructures or by confining the growth along the surface using patterns, dislocations, and catalyst, the present technology allows the direct growth of horizontal nanowires. These nanowires are single crystals with high crystal quality and are used for ZnO memristors.<\/p>\n<div>\n<div><\/div>\n<\/div>\n<p>\u00a0<\/p>\n<p>\u00a0<\/p>\n<p>Publications:<\/p>\n<ul>\n<li>Abdiel Rivera, Anas Mazady and Mehdi Anwar, ZnMg\/ZnO Core-Shell Structures for Gas Sensing, <em> J. Hi. Spe. Ele. Syst.<\/em> 24, 1550010 (2015)<\/li>\n<li>Abdiel Rivera, Anas Mazady and Mehdi Anwar, \u201cEnergy Harvesting Leveraging Piezoelectric Property of ZnO Nanorods\u201d, <em> J. Hi. Spe. Ele. Syst.<\/em> 24, 1520013 (2015)<\/li>\n<li>Abdiel Rivera, Anas Mazady and Mehdi Anwar, \u201cOptimized Growth of ZnO Nanowires and Nanorods Using MOCVD\u201d, <em> J. Hi. Spe. Ele. Syst.<\/em> 24, 1520014 (2015)<\/li>\n<li>Anas Mazady, Abdiel Rivera, Kiarash Ahi and Mehdi Anwar, \"Optical Parameters of ZnMgO\/ZnO Core-Shell Structures in THz Regime\",\u00a0<em>SPIE, Terahertz Physics, Devices and Systems IX: Advanced Applications in Industry and Defense<\/em>, Baltimore, MD, April 20-24, 2015.<\/li>\n<li>Abdiel Rivera, Anas Mazady and Mehdi Anwar, \u201cCo-axial Core-Shell ZnMgO\/ZnO NWs\u201d, Solid State Electronics, Vol. 104, pp.126-130, February 2015.<\/li>\n<li>Abdiel Rivera, John Zeller, Ashok Sood, and Mehdi Anwar, \u201cA Comparison of ZnO Nanowires and Nanorods Grown Using MOCVD and Hydrothermal Processes\u201d, <em> Electron. Mater., <\/em>Vol. 42, No. 5, pp. 894-900, May 1, 2013.<\/li>\n<li>Anas Mazady, Abdiel Rivera, and Mehdi Anwar, \u201cOptical Parameter of Zn<sub>1-x<\/sub>Mg<sub>x<\/sub>O Nanowires in THz Regime\u201d<em> Solid State Electronics<\/em>, vol. 101, pp. 8-12, November 2014.<\/li>\n<li>Abdiel Rivera,\u00a0Anas Mazady,\u00a0Kiarash Ahi and Mehdi Anwar, \"Variation of ZnMgO Properties upon Growth Technique in THz Spectrum\",<em>SPIE, Terahertz Physics, Devices and Systems IX: Advanced Applications in Industry and Defense<\/em>, Baltimore, MD, April 20-24, 2015.<\/li>\n<li>Anas Mazady, Abdiel Rivera and Mehdi Anwar, \u201cOptimization of Annealing Conditions for ZnO-based Thin Films Grown Using MOCVD\u201d, MRS Proceedings, Vol 1675, 2014.<\/li>\n<li>Abdiel Rivera, Anas Mazady and Mehdi Anwar, \u201cLow Temperature Growth of Horizontal ZnO Nanorods, MRS Proceedings, Vol. 1707, 2014<\/li>\n<li>Anas Mazady, Abdiel Rivera and Mehdi Anwar, \u201cEffect of Annealing on Structural and Optical Properties of ZnO Nanowires\u201d, MRS Proceedings, Vol 1675, 2014.<\/li>\n<li>Mehdi F. Anwar, Abdiel Rivera,\u00a0Anas Mazady, Hung Chi Chou, John W. Zeller, and Ashok K. Sood,\u00a0\"ZnMgO Solar Blind Detectors: from Material to Systems\",\u00a0<em>Proc. SPIE<\/em><em>\u00a0<\/em>8868, Infrared Sensors, Devices, and Applications III,\u00a088680B, September 19, 2013<em>.<\/em><\/li>\n<li>Abdiel Rivera,M Anas Mazady, John Zeller,\u00a0Mehdi Anwar, Tariq Manzur, and Ashok Sood, \"ZnO Nanowire Growth and Characterization for UV Detection and Imaging Applications\",\u00a0<em> SPIE 8711,\u00a0<\/em>Sensors, and Command, Control, Communications, and Intelligence (C3I) Technologies for Homeland Security and Homeland Defense XII, 871116, June 6, 2013.<\/li>\n<li>Abdiel Rivera, Mehdi Anwar, John W. Zeller, Tariq Manzur, Ashok K. Sood, \"ZnO nanowire UV detector technology for marine boundary layer\", <em>SPIE Defense, Security, and Sensing, May 1, 2013<\/em>, Baltimore, Maryland<\/li>\n<li>Abdiel Rivera,\u00a0Anas Mazady, John Zeller, Mehdi Anwar, Tariq Manzur, and Ashok Sood, \"MOCVD Growth of ZnO Nanowire Arrays for Advanced UV Detectors\",\u00a0<em> Soc. Optics Photonics,<\/em>86260B-86260B-7, March 18, 2013<em>.<\/em><\/li>\n<li>Abdiel Rivera, Anas Mazady, Mehdi Anwar, John W. Zeller, Tariq Manzur, Ashok K. Sood, \" MOCVD growth of ZnO nanowires arrays for advanced UV detectors \", SPIE Photonic West, Conference Volume 8626<em>, Feb 02, 2013 San Francisco, CA<\/em><\/li>\n<li>Abdiel Rivera; Aurora Edington; John Zeller; Mehdi Anwar, \"Energy scavenging using ZnO nanorods grown on flexible substrates,\" Lester Eastman Conference on High Performance Devices (LEC), 2012 , vol., no., pp.1,4, 7-9 Aug. 2012, doi: 10.1109\/lec.2012.6410973<\/li>\n<\/ul>\n<\/div>\n<\/div><\/div><\/div><\/div><\/div>","protected":false},"excerpt":{"rendered":"<p>Zinc Oxide is a wide band gap semiconductor with a relatively large exciton energy of 60\u202fmeV, and longitudinal optical phonon energy of 72\u202fmeV. ZnO can be grown in any nanostructure such as nanoribbons, nanowires, nanorods, films, core-shell, among others, to be implemented in a variety of applications improving the current state of the art. In [&hellip;]<\/p>\n","protected":false},"author":66,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"page-no-title-breadcrumb.php","meta":{"footnotes":""},"class_list":["post-77","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.ee.uconn.edu\/anwar-research\/wp-json\/wp\/v2\/pages\/77","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ee.uconn.edu\/anwar-research\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.ee.uconn.edu\/anwar-research\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.ee.uconn.edu\/anwar-research\/wp-json\/wp\/v2\/users\/66"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ee.uconn.edu\/anwar-research\/wp-json\/wp\/v2\/comments?post=77"}],"version-history":[{"count":12,"href":"https:\/\/www.ee.uconn.edu\/anwar-research\/wp-json\/wp\/v2\/pages\/77\/revisions"}],"predecessor-version":[{"id":351,"href":"https:\/\/www.ee.uconn.edu\/anwar-research\/wp-json\/wp\/v2\/pages\/77\/revisions\/351"}],"wp:attachment":[{"href":"https:\/\/www.ee.uconn.edu\/anwar-research\/wp-json\/wp\/v2\/media?parent=77"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}