The growth mechanism of the Si $⟨110⟩$ faceted dendrite was studied using an in situ observation technique. We directly observed the growth process of Si faceted dendrites from Si melts. It was found that the shape of the $⟨110⟩$ faceted dendrite during growth is markedly different from that of the $⟨112⟩$ faceted dendrite; the tip of the $⟨110⟩$ faceted dendrite is narrow while that of the $⟨112⟩$ faceted dendrite is wide. We present a scheme for the growth shapes of the faceted dendrites based on the experimental evidences.

We investigated the effects of B/Ge codoping on the minority carrier lifetime in gallium (Ga)-doped Czochralski-silicon (CZ-Si) crystals. Minority carrier lifetime decreased from 28 to $0.1\mu \text{s}$ when the B concentration was increased from $1\times {10}^{15}$ to $1\times {10}^{17}{\text{cm}}^{-3}$ in Ga/B codoped CZ-Si crystals. The minority carrier lifetime increased from 30 to $76\mu \text{s}$ with increasing Ge concentration from $1\times {10}^{17}$ to $2\times {10}^{20}{\text{cm}}^{-3}$ in Ga/Ge codoped CZ-Si crystals. Light-induced degradation experiments showed that Ga/B codoped CZ-Si degraded rapidly, while Ga/Ge codoped CZ-Si showed no degradation. Moreover, the flow pattern defect density related to grown-in microdefects in as-grown Ga/Ge codoped CZ-Si decreased with increasing Ge concentration. The experimental results are explained using a defect reaction model based on the formation of Ge-vacancy-oxygen dimer complexes in the CZ-Si crystal during postgrowth cooling.

Good model systems are required in order to understand crystal growth processes because, in many cases, precise incorporation processes of atoms or molecules cannot be visualized easily at the atomic or molecular level. Using a transmission-type optical microscope, we have successfully observed in situ adsorption, desorption, surface diffusion, lattice defect formation, and kink incorporation of particles on growth interfaces of colloidal crystals of polystyrene particles in aqueous sodium polyacrylate solutions. Precise surface transportation and kink incorporation processes of the particles into the colloidal crystals with attractive interactions were observed in situ at the particle level. In particular, contrary to the conventional expectations, the diffusion of particles along steps around a two-dimensional island of the growth interface was not the main route for kink incorporation. This is probably due to the number of bonds between adsorbed particles and particles in a crystal; the number exceeds the limit at which a particle easily exchanges its position to the adjacent one along the step. We also found novel desorption processes of particles from steps to terraces, attributing them to the assistance of attractive forces from additionally adsorbing particles to the particles on the steps.

Dislocation-free tetragonal hen egg white (HEW) lysozyme crystals were grown from a seed crystal in a cell. The rates of tetragonal HEW lysozyme crystal growth normal to the (110) and (101) faces with and without a 1-MHz external electric field were measured. A decrease in the typical growth rates of the crystal measured under an applied field at 1 MHz was observed, although the overall driving force increased. Assuming that the birth and spread mechanism of two-dimensional nucleation occurs, an increase in the effective surface energy of the step ends was realized in the presence of the electric field, which led to an improvement in the crystal quality of the tetragonal HEW lysozyme crystals. This article also discusses the increase in the effective surface energy of the step ends with respect to the change in the entropy of the solid.