Defects in GaSe grown by Bridgman method

Abstract

Optical quality GaSe crystals have been grown by vertical Bridgman method. The structural properties and micromorphology of a cleaved GaSe(001) surface have been evaluated by RHEED, SEM and AFM. The cleaved GaSe(001) is atomically flat with as low roughness as ∼0.06 nm excepting local hillock type defects. The hillock-type formations are round-shaped with a bottom diameter of ∼200 nm and a height of ∼20-35 nm. The drastic depletion of the hillock material by gallium has been indicated by EDX measurements.

Crystal growth of Bi2Te3 and noble cleaved (0001) surface properties

“…The superposition of wide Kikuchi lines and crystal reflexes is evident, and that verifies an excellent surface structural quality. There is no amorphous component detected at the cleaved surface that is similar to the cleaved surface structural quality previously observed in the layered crystals of GaSe, Pb 2 MoO 5 and AWO 4 (A¼ Zn, Cd) wolframite-type tungstates without additional surface treatments [55][56][57][63][64][65].…”

“…A system of several flat terraces is detected for this field. However, contrary to the previous results obtained for the GaSe and Bi 2 Se 3 (0001) cleaved surface, the large area terraces were not found at the Be 2 Te 3 (0001) surface [55,66]. Also, it should be pointed that the scattered mesoscale structural defects, previously [45].…”

“…However, the conical ampoule tip resulted in the geometrical selection of the single grain at the initial growth stages. The crystallographic orientation of the grain was (0001) plane nearly along the growth axis that is a common feature of layered chalcogenide crystals [19,[52][53][54][55].…”

High-Quality GaSe Single Crystal Grown by the Bridgman Method

“…However, most GaSe materials used to fabricate 2D GaSe devices through mechanical exfoliation were bought from commercial vendors, making it difficult to fully understand the properties of the materials. There have been many attempts to grow GaSe crystals [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ], but the growth of high-quality bulk GaSe crystal is still a challenge. The great difference in saturation vapor pressure of the components Se and Ga can cause non-stoichiometry of a melt-grown crystal composition.…”

Terahertz generation from electron- and neutron-irradiated semiconductor crystal surfaces

“…Because of a pronounced layered structure, the GaSe (0 0 1) optical surface can be prepared by mechanical cleavage [5,[13][14][15][16]. Nevertheless, there is only one work in which terahertz generation from the GaSe (0 0 1) surface was tested by experimental methods [1].…”