Technische Physik, Wilhelm-Conrad-Röntgen-Research Center for Complex Material Systems, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany.
Nanotechnology. 2009 Dec 16;20(50):505601. doi: 10.1088/0957-4484/20/50/505601. Epub 2009 Nov 12.
We demonstrate an optimized molecular beam epitaxial growth procedure of InAs quantum dots (QDs) capped by a low nitrogen content GaInAs(N) quantum well to obtain single QD emission at telecommunication wavelengths. Technical separation of the nitrogen radio frequency plasma source to a second chamber does allow formation of InAs QDs without nitrogen incorporation. Thereby, optical quality degradation is avoided and by additional careful separation of the GaInAsN cap from the InAs QD layer with a partial GaInAs cap of nominal 4 nm thickness we achieve comparatively bright single dot emission above 1300 nm at 8 K. Micro-photoluminescence spectroscopy on single QDs reveal excitonic and biexcitonic emission at 939.8 meV ( approximately 1.319 microm) and 934.6 meV ( approximately 1.327 microm), respectively. Hence, InAs/GaAs(N) QDs can be considered as to be a promising system for use as single photon sources emitting in the 1.3 microm telecommunication band, with prospects for an extension to even longer wavelengths.
我们展示了一种优化的分子束外延生长工艺，在砷化铟量子点（QDs）上生长一层低氮含量的砷化镓铟氮（GaInAs(N)）量子阱，以获得在电信波长下的单量子点发射。将氮射频等离子体源技术分离到第二个腔室中，可以在不掺入氮的情况下形成砷化铟量子点。从而避免了光学质量的退化，并且通过在 GaInAsN 盖层和具有名义上 4nm 厚度的部分 GaInAs 盖层之间进行额外的仔细分离，我们在 8K 下实现了相对较亮的单点发射，波长超过 1300nm。对单个量子点的微荧光光谱分析显示，在 939.8meV（约 1.319μm）和 934.6meV（约 1.327μm）处分别有激子和双激子发射。因此，InAs/GaAs(N) QDs 可以被认为是一种很有前途的系统，可用作在 1.3μm 电信波段发射的单光子源，有望扩展到更长的波长。
