Piezoresistance in CdIn₂S₄

Abstract

Abstract Piezoresistance of n‐type CdIn 2 S 4 single crystals is measured for various directions of the crystal axis. The values at room temperature are isotropic but large, in particular for degenerate samples, compared with those for materials which have spherical energy surfaces. The large values of the piezoresistance of CdIn 2 S 4 is found to be due to its long time relaxation. The values measured immediately after the application of the stress are small and also isotropic, consistent with the spherical band model and are π 11 = −17.2 × 10 −7 , π 12 = 3.24 × 10 −7 , and π 44 = −17.2 × 10 −7 cm 2 /N. The same results are obtained by measurements at low temperatures. The time relaxation of the piezoresistance may be due to trapping centers in the crystals the depth of which depends on the stress and this is confirmed experimentally by measurements of the thermally stimulated currents under various strengths of the stress.