Transport properties of n-type CuInSe2

The electrical properties of as-grown n-type CuInSe2 single crystal are studied between 80 and 300 K. The sample, which is highly compensated, has a shallow donor level of ionization energy of about 6 meV. The mobility data are analysed by taking into account the scattering by ionized impurities, acoustic and polar optical phonons. The conduction band deformation potential is found to be 19.5 eV. The thermal conductivity of the same sample is measured between 4 and 80 K. The data can be explained by considering the scattering of phonons by boundary, impurities, umklapp, and normal processes. The low value of the correction factor F = 0.34, is interpreted as due to the scattering of phonons by extended defects originating from the large microscale fluctuations in the composition of CuInSe2. (author)