Light emission with a wavelength of 1272 nm at room temperature (RT) from self-assembled InAs quantum dots embedded in the GaAs matrix has been obtrained. Growth interruption during the formation of InAs quantum dots (QDs) on a GaAs (100) substrate has been investigated in detail. 1.9 mono layers (MLs) of an InAs QD nucleation layer was grown continuously to form a "seed" with high density. Further, the supply of up to 3 MLs of InAs with a growth interruption of 15 s for every 0.11 ML showed that photoluminescence intensity was improved by 23 times and redshifted the photoluminescence emission nearly 42 nm. The continuous growth up to 1.9 MLs helped to double the dot density. 3.3 MLs of InAs embedded in a GaAs matrix, grown using interruption showed a strong RT photoluminescence peak at around 1272 nm with a very narrow FWHM of 27.1 meV.
We present the results on the monolithic integration of self-assembled GaAs micromirrors with light emitting diodes. The micromirrors were self-assembled by the strain-driven mechanism, which control the micromirror standing position and flatness. The device epi-layer structure and the fabrication processes were optimized. Self-locking mechanism was also employed to precisely position and enhance the mechanical strength of the assembled micromirrors. Light emission was observed on the integrated devices. For the first time, the effectiveness of the self-assembled micromirrors was confirmed in the monolithic integration with LEDs on GaAs. This result shows the feasibility of GaAs-based micro-opto-electromechanical systems for photonics applications.
We report the high-density light-emitting diodes (LEDs) using lateral junction for LED printer and other applications. Semi-insulating GaAs (311)A substrates were patterned to create (100) sidewall. GaAs/AlxGa1-xAs epilayers were grown on the patterned substrate using the amphoteric silicon as a dopant, which forms the lateral p-n junction. For the first time, high-density (2400 dots per inch) LED arrays were fabricated using the lateral junction with device width of 10.6 micron. Light emission spectrum shows a single peak at a wavelength of 813 nm with FWHM of 56 nm at room temperature. The same method can be used to fabricate LED arrays with higher device densities for applications in high resolution LED printers, displays and other applications.