Regensburg 2016 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 50: Gallium Nitride: Fabrication and Characterization

HL 50.1: Vortrag

Mittwoch, 9. März 2016, 09:30–09:45, H17

Molecular beam epitaxy and characterization of InGaN nanowires on Si (111) — •Saskia Weiszer, Andreas Zeidler, Maximilian Kolhep, and Martin Stutzmann — Walter Schottky Institut and Physics Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany

Multi-junction solar cells have received wide attention as each cell can absorb different wavelengths of the solar spectrum which leads to an increased energy conversion efficiency. InGaN has a variable band gap from 0.7 to 3.4eV that covers nearly the whole solar spectrum. Combined with Si, theoretical considerations show that an InGaN/Si tandem solar cell could be an optimal implementation of a double-junction cell. Especially at an In content of 46%, it is expected that a resonant tunnel junction is formed between both cells. Furthermore, the cell efficiency could be increased by growing nanowires to enhance optical properties and to reduce structural defects, since the lattice mismatch strain can relax through the nanowire sidewalls. As first step towards such an InGaN/Si solar cell, the growth of high quality InN nanowires directly on Si(111) substrates by molecular beam epitaxy was studied. By varying the applied growth parameters, namely substrate temperature and III/V-ratio, different growth regimes were identified and the InN nanowire growth was optimized. As next step towards an InGaN/Si solar cell, the growth of InGaN nanowires with increasing Ga content was investigated. Recent results on the determination of the Ga content by energy dispersive X-ray spectroscopy, Raman spectroscopy and photoluminescence measurements will be presented.