Dresden 2006 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 50: Poster II

HL 50.35: Poster

Donnerstag, 30. März 2006, 16:30–19:00, P3

Diamond zinc oxide heterojunction — •Peter Geithner, Jürgen Ristein, and Lothar Ley — Technische Physik, Universität Erlangen-Nürnberg, Germany

A favourable couple for a wide band gap heterojunction is p-type diamond and zinc oxide that is naturally n-type. With a band gap of 3.5 eV for zinc oxide this heterojunction has the potential for a UV emitting LED.

The growth habit of zinc oxide on the diamond (100) and (111) face is investigated. Zinc oxide layers are grown in three ways. Chemical vapour transport is performed in closed silica tubes in a nitrogen atmosphere containing 10% hydrogen. Deposition of textured zinc oxide films is achieved with a source temperature of 800^∘C and applying a linear temperature transient starting at 500^∘C and increasing to 700^∘C within 30 minutes to the sample. The resulting 5µm thick film is characterized by optical and scanning electron microscopy. Films of 1µm thickness are deposited by DC sputtering or by RF magnetron sputtering in an argon atmosphere with 25% oxygen content.

Crystal quality and impurity content in diamond and zinc oxide were investigated by cathodoluminescence (CL) spectroscopy. The CL spectra of the zinc oxide layers show sharp (<8 meV FWHM) exciton lines and a defect band centred around 2.48 eV photon energy.