INTRODUCTION Si/Si1−xGex superlattices are promising candidates for thermoelectric energy conversion applications [1, 2], as the phonon transport through them can be inhibited while maintaining desirable electrical transport properties. No comprehensive experimental study has been performed to map the thermal conductivity design space accessible by Si/Ge nanocomposites. By using atomistic model...

We report on a detailed study of the dependence of the vibrational modes in rapid thermal chemical vapor deposited Si1−x−yGexCy films on the substitutional carbon concentration. Si1−x−yGexCy films were investigated using Raman and infrared spectroscopy with x varying in the range of 10%–16% and y in the range of 0%–1.8%. The introduction of C into thin SiGe layers reduces the average lattice co...

We investigate thermal transport in Si/Ge and Si1−xGex /Si1−yGey alloy superlattices based on solving the single-mode phonon Boltzmann transport equation in the relaxation-time approximation and with full phonon dispersions. We derive an effective interface scattering rate that depends both on the interface roughness (captured by a wave-vector-dependent specularity parameter) and on the efficie...

We study the metal-insulator transition in two sets of amorphous Si1−xNix films. The sets were prepared by different, electron-beam-evaporation-based technologies: evaporation of the alloy, and gradient deposition from separate Ni and Si crucibles. The characterization included electron and scanning tunneling microscopy, glow discharge optical emission spectroscopy, and Rutherford back scatteri...

The effect of optical illumination on DC and dynamic performance of Si1-xGex based double drift region (DDR) (p+pnn+) IMPATT diode operating at W-Band is investigated and compared with its Silicon counterpart. Top Mounted (TM) and Flip Chip (FC) structures are chosen and the composition of photocurrent is altered by shining light on the p+ side and n+ side of the device through optical windows....

High-energy transport properties of charge carriers in ternary random Si1−x−yGexCy alloys are investigated using Full-Band Monte Carlo simulations. Models for scattering mechanisms include phonon scattering, impact ionization and alloy scattering. Phonon scattering rates are wave-vector dependent and calculated consistently with the Full-Band structure. Impact ionization rates are modeled using...

We investigated the types of dendrites grown in Si1−xGex (0 < x 1) melts, and also initiation dendrite growth during unidirectional Si1-xGex alloys. is a semiconductor alloy with completely miscible-type binary phase diagram. Therefore, alloys are promising for use as epitaxial substrates electronic devices owing to fact that their band gap lattice constant can be tuned by selecting proper c...

Ab initio calculations have been carried out to investigate the H-atom migration and H2 desorption on the mixed SiGe(100)-2×1 surface using the Si9-xGexH13, Si14GeH19 and Si13Ge2H19 cluster models. The H2 recombinative desorption is the rate-determining step in hydrogen migration and desorption on SiGe(100) surface since the energy barrier of H-atom migration is generally lower than that of H2 ...

Fast optical interconnects together with an associated light emitter that are both compatible with conventional Si-based complementary metal-oxide-semiconductor (CMOS) integrated circuit technology is an unavoidable requirement for the next-generation microprocessors and computers. Self-assembled Si/Si1−xGex nanostructures (NSs), which can emit light at wavelengths within the important optical ...

The dependence of band-to-band tunneling in p+-Si1−xGex /n+-Si1−xGex homojunctions on Ge fraction and electric field is investigated in the range 2–3×108 V/m. Negative differential resistance (NDR) in forward bias is observed for each device with the highest peak tunneling-current density of 8.2 kA/cm2 without any postannealing step. Reverse-biased band-to-band tunneling, as relevant for tunnel...