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Low voltage electron-beam lithography based InGaAs/GaAs quantum dot arrays with 1 meV luminescence linewidths

1997; American Institute of Physics; Volume: 15; Issue: 6 Linguagem: Inglês

10.1116/1.589737

1520-8567

K. H. Wang, A. Pecher, E. Höfling, A. Forchel,

Near-Field Optical Microscopy

We have developed InGaAs/GaAs quantum dots with diameters down to about 50 nm on shallow quantum wells using low voltage electron-beam lithography and wet chemical etching. Due to the low energy of the e-beam of 2.5 keV the proximity effect is negligible and arrays of quantum dots with a homogeneous diameter could be fabricated. By using low excitation photoluminescence spectroscopy we observe a clear shift of the dot emission to higher energy due to lateral quantization that amounts to 6 meV in the smallest structures. The linewidth of the luminescence of the dot arrays of about 1.5 meV is almost independent of the dot size, i.e., the inhomogeneous broadening due to the patterning induced lateral size fluctuation is found to be negligible in the present structures.