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HL: Fachverband Halbleiterphysik
HL 35: Poster I
HL 35.38: Poster
Tuesday, March 8, 2016, 15:00–19:00, Poster A
Influence of acceptor concentration on burn-in effects in AlGaN-based deep UV LEDs — •Jakob Jordan1, Martin Guttmann1, Frank Mehnke1, Johannes Enslin1, Simon Kapanke1, Tim Wernicke1, Mickael Lapeyrade2, Markus Weyers2, Sven Einfeldt2, and Michael Kneissl1,2 — 1Technische Universität Berlin, Institut für Festkörperphysik, Berlin, Germany — 2Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Berlin, Germany
Light in the deep ultraviolet (UVC) spectral range is used in diverse areas such as sewage water treatment and gas sensing. The toxicity and relative bulkiness of conventional UV mercury lamps necessitates development of light emitting diodes (LEDs) operating in this wavelength region. In this contribution, the optical and electronic properties of AlGaN-based LEDs emitting near 233 nm are analyzed with regards to a variation of the magnesium doping concentration in the electron blocking heterostructure and p-side superlattice. Electroluminescence (EL) measurements are used to determine changes in emission spectrum, light output power, device yield, and temperature response. During measurements, burn-in effects were discovered for LEDs with low Mg-doping. These burn-in effects produce a significant increase in output power that persists after cool down. Annealing in a high temperature environment does not lead to an increase in power, implying that the injected charge carriers are aiding in the activation process. The influence of time, temperature, and current on the observed burn-in effects will be presented and possible explanations will be discussed.