Signatures of Quantized Energy States in Solution-Processed Ultrathin Layers of Metal-Oxide Semiconductors and Their Devices

Handle URI:
http://hdl.handle.net/10754/575642
Title:
Signatures of Quantized Energy States in Solution-Processed Ultrathin Layers of Metal-Oxide Semiconductors and Their Devices
Authors:
Labram, John G.; Lin, Yenhung; Zhao, Kui ( 0000-0001-9348-7943 ) ; Li, Ruipeng; Thomas, Stuart R.; Semple, James; Androulidaki, Maria; Sygellou, Lamprini; McLachlan, Martyn A.; Stratakis, Emmanuel; Amassian, Aram ( 0000-0002-5734-1194 ) ; Anthopoulos, Thomas D.
Abstract:
Physical phenomena such as energy quantization have to-date been overlooked in solution-processed inorganic semiconducting layers, owing to heterogeneity in layer thickness uniformity unlike some of their vacuum-deposited counterparts. Recent reports of the growth of uniform, ultrathin (<5 nm) metal-oxide semiconductors from solution, however, have potentially opened the door to such phenomena manifesting themselves. Here, a theoretical framework is developed for energy quantization in inorganic semiconductor layers with appreciable surface roughness, as compared to the mean layer thickness, and present experimental evidence of the existence of quantized energy states in spin-cast layers of zinc oxide (ZnO). As-grown ZnO layers are found to be remarkably continuous and uniform with controllable thicknesses in the range 2-24 nm and exhibit a characteristic widening of the energy bandgap with reducing thickness in agreement with theoretical predictions. Using sequentially spin-cast layers of ZnO as the bulk semiconductor and quantum well materials, and gallium oxide or organic self-assembled monolayers as the barrier materials, two terminal electronic devices are demonstrated, the current-voltage characteristics of which resemble closely those of double-barrier resonant-tunneling diodes. As-fabricated all-oxide/hybrid devices exhibit a characteristic negative-differential conductance region with peak-to-valley ratios in the range 2-7.
KAUST Department:
Materials Science and Engineering Program; Physical Sciences and Engineering (PSE) Division; Solar and Photovoltaic Engineering Research Center (SPERC); Organic Electronics and Photovoltaics Group
Publisher:
Wiley-Blackwell
Journal:
Advanced Functional Materials
Issue Date:
13-Feb-2015
DOI:
10.1002/adfm.201403862
Type:
Article
ISSN:
1616301X
Sponsors:
J.G.L., Y.-H.L., J.S., and T.D.A. are grateful to Dutch Polymer Institute (DPI) S-PLORE Grant No. 735 and European Research Council (ERC) AMPRO Project No. 280221 for financial support. CHESS is supported by the NSF & NIH/NIGMS via NSF Award No. DMR-1332208.
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Materials Science and Engineering Program; Solar and Photovoltaic Engineering Research Center (SPERC)

Full metadata record

DC FieldValue Language
dc.contributor.authorLabram, John G.en
dc.contributor.authorLin, Yenhungen
dc.contributor.authorZhao, Kuien
dc.contributor.authorLi, Ruipengen
dc.contributor.authorThomas, Stuart R.en
dc.contributor.authorSemple, Jamesen
dc.contributor.authorAndroulidaki, Mariaen
dc.contributor.authorSygellou, Lamprinien
dc.contributor.authorMcLachlan, Martyn A.en
dc.contributor.authorStratakis, Emmanuelen
dc.contributor.authorAmassian, Aramen
dc.contributor.authorAnthopoulos, Thomas D.en
dc.date.accessioned2015-08-24T08:34:52Zen
dc.date.available2015-08-24T08:34:52Zen
dc.date.issued2015-02-13en
dc.identifier.issn1616301Xen
dc.identifier.doi10.1002/adfm.201403862en
dc.identifier.urihttp://hdl.handle.net/10754/575642en
dc.description.abstractPhysical phenomena such as energy quantization have to-date been overlooked in solution-processed inorganic semiconducting layers, owing to heterogeneity in layer thickness uniformity unlike some of their vacuum-deposited counterparts. Recent reports of the growth of uniform, ultrathin (<5 nm) metal-oxide semiconductors from solution, however, have potentially opened the door to such phenomena manifesting themselves. Here, a theoretical framework is developed for energy quantization in inorganic semiconductor layers with appreciable surface roughness, as compared to the mean layer thickness, and present experimental evidence of the existence of quantized energy states in spin-cast layers of zinc oxide (ZnO). As-grown ZnO layers are found to be remarkably continuous and uniform with controllable thicknesses in the range 2-24 nm and exhibit a characteristic widening of the energy bandgap with reducing thickness in agreement with theoretical predictions. Using sequentially spin-cast layers of ZnO as the bulk semiconductor and quantum well materials, and gallium oxide or organic self-assembled monolayers as the barrier materials, two terminal electronic devices are demonstrated, the current-voltage characteristics of which resemble closely those of double-barrier resonant-tunneling diodes. As-fabricated all-oxide/hybrid devices exhibit a characteristic negative-differential conductance region with peak-to-valley ratios in the range 2-7.en
dc.description.sponsorshipJ.G.L., Y.-H.L., J.S., and T.D.A. are grateful to Dutch Polymer Institute (DPI) S-PLORE Grant No. 735 and European Research Council (ERC) AMPRO Project No. 280221 for financial support. CHESS is supported by the NSF & NIH/NIGMS via NSF Award No. DMR-1332208.en
dc.publisherWiley-Blackwellen
dc.subjectEnergy quantizationen
dc.subjectResonant tunneling diodesen
dc.subjectSemiconducting oxidesen
dc.subjectSolution-processed semiconductorsen
dc.subjectZinc oxideen
dc.titleSignatures of Quantized Energy States in Solution-Processed Ultrathin Layers of Metal-Oxide Semiconductors and Their Devicesen
dc.typeArticleen
dc.contributor.departmentMaterials Science and Engineering Programen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentSolar and Photovoltaic Engineering Research Center (SPERC)en
dc.contributor.departmentOrganic Electronics and Photovoltaics Groupen
dc.identifier.journalAdvanced Functional Materialsen
dc.contributor.institutionDepartment of Physics, Blackett Laboratory, Imperial College LondonLondon, United Kingdomen
dc.contributor.institutionDutch Polymer Institute (DPI), P. O. Box 902Eindhoven, Netherlandsen
dc.contributor.institutionCornell High Energy Synchrotron Source, Cornell UniversityIthaca, NY, United Statesen
dc.contributor.institutionFoundation for Research and Technology Hellas (FORTH), Institute of Electronic Structure and Lasers (IESL), Heraklion Crete and Institute of Chemical Engineering Sciences (ICEHT)Patras, Greeceen
dc.contributor.institutionDepartment of Materials, Royal School of Mines, Imperial College LondonLondon, United Kingdomen
kaust.authorZhao, Kuien
kaust.authorAmassian, Aramen
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