Keun Wook Shin

Growth of Si-doped GaInP on Ge-on-Si substrates and its photoluminescence characteristics

Optical properties of Si-doped GaInP grown on Ge-on-Si substrates were investigated using photoluminescence (PL). Similar to spontaneously ordered GaInP, two peaks were observed around 1.74 and 1.85 eV at 19 K; however, no satellite peaks were observed in the selected-area diffraction pattern. Based on temperature-dependent PL, the peak at 1.74 eV was attributed to the donor–acceptor pair transition caused by the amphoteric characteristics of Si and/or Ge from the dopant and/or substrate. In addition, the S-shape in the temperature dependence of the 1.85 eV peak was attributed to the interaction of the donor levels with the conduction band of GaInP.

Growth of GaN Columns and Microstructures on (111) Si by Using Ge Layer via Metal Organic Chemical Vapor Deposition

We demonstrate the successful growth of GaN columnar and microdisk structures on a (111) Ge/Si substrate via metal organic chemical vapor deposition. X-ray diffraction and energy disperse spectroscopy results reveal that the well aligned GaN nanocolumnar structures are grown on a Si substrate by using the Ge layer. The relatively higher growth temperature induces a change in surface morphology of GaN from columnar to microdisk structures. The possible growth mechanism of columnar structured GaN was considered from the Ga-metal/Ge eutectic materials system.