Regensburg 2010 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 34: Poster I: III-V Semiconductors

HL 34.34: Poster

Dienstag, 23. März 2010, 18:30–20:30, Poster D2

InGaN layers in visible LEDs and solar cells — •Samir Hammadi, Joerg Hisek, Holger Jönen, Uwe Rossow, and Andreas Hangleiter — Institut für Angewandte Physik, Technische Universität Braunschweig

By applying InGaN quantum well layers in light emitting heterostructures, efficiencies greater than 80% in the blue-violet wavelength range can be achieved. This requires a high structural perfection of the underlying layers and the active region - grown by metal organic vapour phase epitaxy (MOVPE) - as well as suitable process steps in order to suppress the effects of the remaining dislocations as nonradiative recombination centers. Naturally, it should be possible to utilize similar structures for solar cells. By varying the In content of InGaN, the band gap can be altered between 0.67 * 3.4 eV, covering almost the whole solar emission spectrum. Such a heterostructure would, however, require InGaN layers with a rather high (> 50%)) and low (< 30%) In content. For a high In incorporation relatively low growth temperatures are necessary, making it difficult to achieve high quality layers with conventional MOVPE growth. Plasma assisted molecular beam epitaxy (RF-MBE) may overcome this problem, does, however not enable higher growth temperatures for low indium incorporation. In this contribution we compare high-In quantum wells (30-50%) grown by MOVPE and by MBE and study the influence of defects and recombination centers by analyzing X-ray diffraction, transmission electron microscopy, and photoluminescence data.