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HL: Fachverband Halbleiterphysik

HL 108: Poster: Ultra-fast phenomena / Optical properties / Semiconductor laser / Devices and device concepts

HL 108.26: Poster

Donnerstag, 3. April 2014, 17:00–20:00, P1

GaAs nanowires based avalanche photo diodes — Stepan Shvarkov¹, •Wadim Quiring², Artur Zrenner², Arne Ludwig³, Andreas Dirk Wieck³, and Dirk Reuter¹ — ¹Optoelektronische Materialien und Bauelemente, Universität Paderborn, D-33098 Paderborn — ²Optoelektronik und Spektroskopie an Nanostrukturen, Universität Paderborn, D-33098 Paderborn — ³Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum

Modern planar Si-based avalanche photo diodes (APD) show very high multiplication factors and low dark currents, which makes Si-based planar APDs a versatile detector for single photon detection (SPD). However, in the optical C-band (1.55 µm), these detectors cannot be used and planar APDs based on III-V semiconductors show rather high dark currents. This is a severe drawback for applications in quantum communications. APDs based on nanowires can be an approach to overcome this problem. In the current work we present GaAs nanowire APDs based on planar MBE growth. The nanowires are realized in several nanofabrication steps. First a lateral p-i-n junction is defined by implanting a nominally undoped GaAs layer on an Al_0.95Ga_0.05As buffer layer with Be and Si. The length of the i-region is approximately 10 µm.By electron beam lithography and reactive ion etching nanowires are defined so that one end of the wire is lying in p- and another in n-type regions of the GaAs. The resulting devices show a clear rectifying current-voltage characteristic and allow for large reverse bias before breakdown. Under illumination a large internal amplification is observed, which is attributed to avalanche multiplication.