CdSe quantum dots and their application in surface emitters and micropillars: A comparison to analogous nitride structures
|Detlef Hommel 1, Carsten Kruse 1, Arne Gust 1, Tomohiro Yamaguchi 1, Stephan Figge 1, Kai Otte 1, Henning Lohmeyer 1, Kathrin Sebald 1, Jürgen Gutowski 1, Roland Kröger 1, Angelika Pretorius 1, Andreas Rosenauer 1, Jan Wiersig 2, Norman Bär 2, Frank Jahnke 2|
1. University of Bremen, Institute of Solid State Physics, Kufsteiner Strasse 1, Bremen 28359, Germany
The growth of CdSe quantum dots (QDs) embedded in a ZnMgSSe matrix will be discussed. Laser diodes with CdSe/ZnSSe quantum dot stacks show a superior stability compared to conventional LDs with a quantum well as optically active region. For low power applications CdSe QDs as active region can be a real alternative to other semiconductor materials for the green spectral region. Approaches to reach a single photon emitter at room temperature will be presented. The monolithic growth of a vertical cavity surface emitting laser (VCSEL) requires a reflectivity well above 99%. This can be realized by stacks of distributed Bragg reflectors (DBR). For the low index DBR a short period superlattice ZnCdSSe/MgSe is used. The stop-band can be tuned over the whole visible spectral region. Optically pumped lasing of such a monolithic VCSEL has been obtained. Using a focused ion beam (FIB) for nano-structuring, air gap micropillars can be realized with a very high aspect ratio. The dependence of the optical modes on pillar diameter will be presented including theoretical modelling. First results on CdSe QDs in micropillars show the Purcell effect (enhancement of emission) when such a QD comes in resonance with the cavity mode.
Presentation: Invited oral at E-MRS Fall Meeting 2006, Symposium F, by Detlef Hommel
See On-line Journal of E-MRS Fall Meeting 2006
Submitted: 2006-06-14 11:48 Revised: 2009-06-07 00:44