Print Email Facebook Twitter Spatial conductivity mapping of unprotected and capped black phosphorus using microwave microscopy Title Spatial conductivity mapping of unprotected and capped black phosphorus using microwave microscopy Author de Visser, P.J. (TU Delft QN/Klapwijk Lab; University of Geneva) Chua, Rebekah (National University of Singapore; Student TU Delft) Island, J.O. (TU Delft QN/van der Zant Lab) Finkel, M. (TU Delft QN/Klapwijk Lab; Moscow State Pedagogical University) Katan, A.J. (TU Delft QN/Afdelingsbureau) Thierschmann, R. (TU Delft QN/Klapwijk Lab) van der Zant, H.S.J. (TU Delft QN/van der Zant Lab) Klapwijk, T.M. (TU Delft QN/Klapwijk Lab; Moscow State Pedagogical University) Date 2016-03-30 Abstract Thin layers of black phosphorus present an ideal combination of a 2Dmaterial with a tunable direct bandgap and high carrier mobility. However the material suffers from degradation in ambient conditions due to an oxidation reaction which involves water, oxygen and light. Wehave measured the spatial profile of the conductivity on flakes of black phosphorus as a function of time using scanning microwave impedance microscopy. Amicrowave excitation (3 GHz) allows to image a conducting sample even when covered with a dielectric layer. Weobserve that on bare black phosphorus, the conductivity changes drastically over the whole surface within a day. Wedemonstrate that the degradation process is slowed down considerably by covering the material with a 10 nmlayer of hafnium oxide. It is stable for more than a week, opening up a route towards stable black phosphorus devices in which the high dielectric constant of hafnium oxide can be exploited. Covering black phosphorus with a 15 nmboron nitride flake changes the degradation process qualitatively, it is dominated by the edges of the flake indicating a diffusive process and happens on the scale of days. Subject Black phosphorusBoron nitrideConductivityDegradationHafnium oxideMicrowave impedance microscopy To reference this document use: http://resolver.tudelft.nl/uuid:d886d683-c4dc-4e56-97ce-ae4964909175 DOI https://doi.org/10.1088/2053-1583/3/2/021002 ISSN 2053-1583 Source 2D Materials, 3 (2) Part of collection Institutional Repository Document type journal article Rights © 2016 P.J. de Visser, Rebekah Chua, J.O. Island, M. Finkel, A.J. Katan, R. Thierschmann, H.S.J. van der Zant, T.M. Klapwijk Files PDF Visser_2016_2D_Mater._3_021002.pdf 1.95 MB Close viewer /islandora/object/uuid:d886d683-c4dc-4e56-97ce-ae4964909175/datastream/OBJ/view