Compositional, structural, optical and electrical characterization of CuInTe2 grown by the tellurization of stoichiometric Cu and In in the liquid phase

A new method to grow single crystals with stoichiometry close to 1:1:2 of C uInTe2, an important member of the Cu-III-VI2 family of semiconductors is d escribed. This consists of tellurization in the liquid phase of stoichiomet ric Cu and In and later solidification under directional freezing. It is fo und from energy dispersive spectroscopy that the ingots obtained with the e vaporation temperature (T-t) of Te at 590 and 635 degrees C were very close to the ideal stoichiometry 1:1:2. Samples of all ingots obtained with T-t between 530 and 690 degrees C, as studied by x-ray and differential thermal analysis, were of single phase having chalcopyrite structure and p-type co nductivity. Optical and electrical characterization of different ingots wer e made. The acceptor ionization energy E-A and the density of states effect ive mass m(p)* of the holes are estimated from the temperature dependence o f the hole concentration p in samples of different ingots, m(p)* = (0.78 +/ - 0.02) m(e) agrees quite well with the reported value. From a combined ana lysis of the variation of E-A with p(1/3) and the knowledge of molecularity and valence stoichiometry of each sample, it is established that the shall ow acceptor level observed in different samples with E-A (0) similar or equ al to 30 meV is due to V-In.