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Back Cover: Study of defects and lifetime of green InGaN laser diodes (Phys. Status Solidi A 3/2012)
Author(s) -
Strauss Uwe,
Lermer Teresa,
Müller Jens,
Hager Thomas,
Brüderl Georg,
Avramescu Adrian,
Lell Alfred,
Eichler Christoph
Publication year - 2012
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201290004
Subject(s) - quantum well , laser , materials science , optoelectronics , diode , indium , wavelength , diffraction , cover (algebra) , optics , physics , mechanical engineering , engineering
InGaN quantum wells for direct green lasers with indium concentrations of about 30% are studied by Uwe Strauss and co‐workers (pp. 481–486 ) in respect to defect structure and influence of defects on device lifetime. A new test structure enables them to determine strain relaxation in In‐rich layers by X‐ray diffraction even at typical well thicknesses of few nanometers. The cover shows reciprocal space maps of such a test structure including quantum wells for green lasers and a reference structure, respectively. The authors describe that there is a high risk to generate screw and edge dislocations in the In‐rich quantum wells in non‐optimized structures as verified by transmission electron microscopy. Such defects strongly influence the device lifetime of green lasers. Optimized active layers already enable stable operation over a period of more than 1000 hours at 50 mW constant power at 517 nm emission wavelength with an extrapolated increase of operation current by less than 30% within this time.