Premium
Phosphor‐converted white light from blue‐emitting InGaN microrod LEDs
Author(s) -
Schimpke Tilman,
Mandl Martin,
Stoll Ion,
PohlKlein Bianca,
Bichler Daniel,
Zwaschka Franz,
StrubeKnyrim Johanna,
Huckenbeck Barbara,
Max Benjamin,
Müller Marcus,
Veit Peter,
Bertram Frank,
Christen Jürgen,
Hartmann Jana,
Waag Andreas,
Lugauer HansJürgen,
Strassburg Martin
Publication year - 2016
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.201532904
Subject(s) - light emitting diode , cathodoluminescence , phosphor , optoelectronics , materials science , luminescence , electroluminescence , diode , indium gallium nitride , quantum efficiency , gallium nitride , wafer , green light , quantum well , metalorganic vapour phase epitaxy , epitaxy , optics , nanotechnology , blue light , laser , physics , layer (electronics)
A uniform array of gallium nitride core‐shell microrod (MR) light‐emitting diode (LED) structures was grown by metalorganic vapor phase epitaxy. Defects and the quantum well (QW) luminescence in an individual rod were investigated by scanning tunneling electron microscopy (STEM) and STEM cathodoluminescence. Luminescence with different wavelength was detected from the quantum wells on the semipolar tip facets and the nonpolar sidewalls of the MRs. Furthermore, the MR array is processed into LED chips. The electro‐optical characteristics of the devices are analyzed. Two separate emission bands are distinguished, which are attributed to the QWs on the semipolar tip facets and the nonpolar sidewalls, respectively. To obtain white LEDs, micrograin phosphors were developed which fit in between individual MRs. By using electrophoretic particle deposition, these phosphors are deposited onto the MR LED chips. Color coordinates, color temperature, and device efficiency are evaluated. Blue (top) and phosphor‐converted white (bottom) microrod LEDs on 4″ wafer.