The growth of ZnSe epitaxial layers on GaAs has been examined by Synchrotron radiation topography in order to measure the critical thickness defined as the onset of the first mismatch dislocation. Previous X-ray and photoluminescence measurements, which measure the average strain in the layer, have resulted in 150 nm as the accepted value for the critical thickness. In this paper we discuss the limitations of these previous measurements and demonstrate that the topography measurements show that 95 nm is the critical thickness. The implications of this reduction of the critical thickness of ZnSe by one-third is extended to a discussion of ZnCdSe quantum well layers within laser structures where the onset of dislocations will have a dramatic effect on the device lifetime. Growth of ZnSe on the (211)B GaAs surface has been investigated and the quantum confined Stark effect in piezo-electric quantum well structures has been studied and is reported for Schottky devices.
|Number of pages||8|
|Journal||Molecular Crystals and Liquid Crystals Science and Technology. Section B, Nonlinear optics|
|Publication status||Published - 1997|
|Event||Proceedings of the 1997 International Symposium on Quantum Structures for Photonic Applications, QSPA'97 - Sendai, Jpn|
Duration: 6 Mar 1997 → 8 Mar 1997