Berlin 2015 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 21: Poster IB (Oxide semiconductors; II-VI and group IV semiconductors; Nanotubes and Buckyballs)

HL 21.23: Poster

Monday, March 16, 2015, 15:00–20:00, Poster B

ZnO nanowire Schottky diodes on ITO and FTO substrates: study of the junction by electrical characterization — Alejandra Castro-Carranza¹, •Jairo Cesar Nolasco², Emily T. Tansey¹, Stephanie Bley¹, Olesea Volciuc¹, Tobias Voss³, and Jürgen Gutowski¹ — ¹Institute of Solid State Physics, University of Bremen, Germany — ²Energy and Semiconductor Research Laboratory, Carl von Ossietzky University Oldenburg, Germany — ³Institute of Semiconductor Technology, TU Braunschweig University of Technology, Germany

Zinc oxide nanowires (ZnO NW) have been used in flexible LEDs and solar cells. As important topic for these applications is the study of the junction formed between ZnO NWs and transparent conductive oxides, e.g. fluorine doped tin oxide (FTO) and indium tin oxide (ITO), which are commonly used as front contacts. Their work functions define the nature of the junction with ZnO NWs, i.e. ohmic contacts or Schottky diodes. However, surface defect states on the ZnO NWs can influence such a junction. In the present work we explore the electrical characteristics of junctions based on wet-chemically grown vertical ZnO NW arrays on FTO and ITO by means of their current-voltage characteristics and impedance spectroscopy. We observed that a significant barrier height is formed at the junctions, corresponding to a Schottky diode, and the obtained ideality factors describe that the conduction mechanism occurring at the junctions is affected by tunneling through traps.