Effect of adding Te to layered GaSe crystals to increase the van der Waals bonding force.

The interplanar binding strength of layered GaSe_1-xTe_x crystals was directly measured using a tensile testing machine. The GaSe_1-xTe_x crystals were grown by a low temperature liquid phase solution method under a controlled Se vapor pressure. The stoichiometry-controlled GaSe_1-xTe_x crystal has the ε-polytype structure of GaSe, where the Te atoms are substituted for some of the Se atoms in the GaSe crystal. The effect of adding Te on the bonding strength between the GaSe layers was determined from direct measurements of the van der Waals bonding energy. The bonding energy was increased from 0.023×10⁶ N/m² for GaSe to 0.16×10⁶ N/m² for GaSe_1-xTe_x (x=0.106). [ABSTRACT FROM AUTHOR]