C. RINC~N and B. J. zyxwvutsrq FERNANDEZ: Deformation Potentials in Chalcopyrites 199 phys. stat. sol. (b) zyxwvu 178, 199 (1993) Subject classification: 72.10 and 72.20; S7.16 zyxwvu Centro zyxwvutsr de Estudios de Semiconductores, Depuvtumento de Fisica Fucultud zyxw de Ciencias, Universidud de Los Andes, Mkrida') Deformation Potentials in A"BIVC; Ternary Chalcopyrite Semiconductors BY C. RINCON and B. J. FERNANDEZ Deformation potentials of valence and conduction bands in A"B'VCT chalcopyrite semiconductors are calculated from the variation of the energy gap with temperature and pressure. From a comparison with their binary analogues A1"BV it is found that values of deformation potentials in these compounds are considerably higher than in the binaries which could explain their lower carrier mobility. 1. Introduction The ternary A"B"'C: semiconducting compounds which crystallize in the chalcopyrite structure have received considerable attention recently 11 to 31 because of their possible application in a variety of opto-electronic devices [4 to 61. Systematic studies of transport properties of some of these compounds and also a theoretical analysis of their charge- carrier scattering mechanisms have been published [7 to 111. However, no information has been reported regarding their valence and conduction band deformation potentials, which are very important parameters for a complete analysis of transport data in these compounds because they determine the strength of the acoustic-mode scattering in semiconductors. In A'B"'C~' compounds the deformation potentials of the valence (C,) and conduction (C,) bands have been usually obtained by analyzing the variation of the carrier mobility with temperature using Mathiessen's rule. In this approach the total mobility is calculated by the equation where the sum is taken over the mobilities of charge carriers due to different scattering mechanisms. In order to fit this equation to the experimental mobility data, only the predominant scattering mechanisms are included in the calculation. However, these mechanisms are not clearly identified in the ternary chalcopyrite compounds. Hence, due to the different choices of scattering mechanisms considered in the analysis, discrepancy exists in the values of deformation potentials of A'B"'CY compounds reported by different authors. Thus, for example, the reported values of C, in CuInSe, vary from 13 to 55 eV [12]. By considering the variation of the energy gap with temperature and pressure in A'B"'C:' compounds it has been shown recently [13, 141 that more reliable values of deformation z *) Aparto de Correos 1, Merida 5251, Venezuela,