Enhanced Response Speed of ZnO Nanowire Photodetector by Coating with Photoresist

<div>Schematic diagrams of the carrier transport mechanism of the ZnO NW (cross-section) without photoresist. (a) Oxygen molecules absorbed on the NW surface capture free electrons from the NW to generate <svg height="13.9782pt" id="M6" style="vertical-align:-3.1815pt" version="1.1" viewbox="-0.0498162 -10.7967 20.8725 13.9782" width="20.8725pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M381 665C170 665 44 498 44 318C44 125 188 -15 369 -15C552 -15 703 117 703 333C703 534 550 665 381 665ZM359 629C491 629 601 517 601 306C601 114 502 21 390 21C249 21 146 158 146 346S248 629 359 629Z" id="g121-77"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="747" vert-adv-y="747"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,9.711,3.132)"><path d="M414 144C384 79 371 75 317 75H135L276 221C367 316 408 376 408 465C408 570 327 635 237 635C179 635 131 609 100 575L42 494L67 471C94 510 138 565 205 565C277 565 321 517 321 435C321 348 258 270 195 195C146 137 88 81 33 26V0H411C423 44 433 88 446 135L414 144Z" id="g50-51"></path><glyph.data ascent="3443" descent="-2856" horiz-adv-x="487" vert-adv-y="487"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,14.694,-5.741)"><path d="M556 236V289H56V236H556Z" id="g54-33"></path><glyph.data ascent="3443" descent="-2856" horiz-adv-x="611" vert-adv-y="611"></glyph.data></g></svg>. A depletion region is formed under the surface of ZnO NW; (b) some <svg height="13.9782pt" id="M7" style="vertical-align:-3.1815pt" version="1.1" viewbox="-0.0498162 -10.7967 20.8725 13.9782" width="20.8725pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M381 665C170 665 44 498 44 318C44 125 188 -15 369 -15C552 -15 703 117 703 333C703 534 550 665 381 665ZM359 629C491 629 601 517 601 306C601 114 502 21 390 21C249 21 146 158 146 346S248 629 359 629Z" id="g121-77"></path><glyph.data ascent="989" descent="-360" horiz-adv-x="747" vert-adv-y="747"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,9.711,3.132)"><path d="M414 144C384 79 371 75 317 75H135L276 221C367 316 408 376 408 465C408 570 327 635 237 635C179 635 131 609 100 575L42 494L67 471C94 510 138 565 205 565C277 565 321 517 321 435C321 348 258 270 195 195C146 137 88 81 33 26V0H411C423 44 433 88 446 135L414 144Z" id="g50-51"></path><glyph.data ascent="3443" descent="-2856" horiz-adv-x="487" vert-adv-y="487"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,14.694,-5.741)"><path d="M556 236V289H56V236H556Z" id="g54-33"></path><glyph.data ascent="3443" descent="-2856" horiz-adv-x="611" vert-adv-y="611"></glyph.data></g></svg> ions lose their electrons when the UV light illuminates the ZnO NW. The oxygen escapes from the surface of the nanowire.</div>

Journal of Nanomaterials

fig7

Figure 7

Figure 7: Enhanced Response Speed of ZnO Nanowire Photodetector by Coating with Photoresist 