Doping-induced losses in AlAs/GaAs distributed Bragg reflectors
2001 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 90, no 2, 794-800 p.Article in journal (Refereed) Published
We have studied n- and p-type doping-induced performance degradation of AlAs/GaAs distributed Bragg reflectors (DBRs) for applications in vertical cavity lasers (VCLs). Based on high-accuracy optical reflectance and triple-axis x-ray diffraction measurements on a variety of differently doped DBR structures grown by metalorganic vapor-phase epitaxy, a fitting procedure was employed to extract the doping-dependent optical loss. A striking observation is that the reflectance of these DBRs is much more sensitive to n- than p-type doping incorporation. While in the latter case the loss can be well accounted for by intervalence-band and free-carrier absorption, additional loss mechanisms must be considered for n-type DBRs. We relate the losses to doping-enhanced interdiffusion effects resulting in increased interface scattering. These findings should have important consequences for the design of VCLs, demonstrating the importance of reduced n-type doping concentrations and/or growth temperatures, or the application of alternative device concepts, e.g., employing intracavity contacts.
Place, publisher, year, edition, pages
2001. Vol. 90, no 2, 794-800 p.
vertical-cavity lasers, x-ray-diffraction, room-temperature, continuous-wave, mu-m, gaas, superlattices, heterostructures, interdiffusion, multilayers
IdentifiersURN: urn:nbn:se:kth:diva-20754ISI: 000169660000037OAI: oai:DiVA.org:kth-20754DiVA: diva2:339451
QC 201005252010-08-102010-08-10Bibliographically approved