Premium
The Effect of Substitution of Gallium on the Transport Properties of Polycrystalline GeTe
Author(s) -
Narang Deepa S.,
Jana Manoj K.,
Gupta Uttam
Publication year - 2018
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201700412
Subject(s) - seebeck coefficient , crystallite , gallium , materials science , doping , condensed matter physics , hall effect , valence (chemistry) , thermoelectric effect , electrical resistivity and conductivity , electron mobility , valence band , electron , analytical chemistry (journal) , band gap , thermodynamics , thermal conductivity , chemistry , metallurgy , optoelectronics , physics , composite material , organic chemistry , chromatography , quantum mechanics
We have investigated the electron transport properties of polycrystalline Ge 1− x Ga x Te alloys. Ga‐incorporation in GeTe has a nonmonotonic effect on its electrical conductivity which decreases slightly at low doping levels, but significantly at high doping levels ( x ≥ 0.06) due to a concomitant reduction of hole‐concentration and mobility. Plausible Ga‐doping mechanisms determining these trends have been discussed. The Seebeck coefficient of GeTe does not enhance with Ga content as much as with Sb, Bi or In content at similar hole‐concentrations. Based on the theoretical Pisarenko plots and estimated effective carrier masses in Ge 1− x Ga x Te alloys, the observed behavior of Seebeck coefficient is rationalized on the basis of relative orbital energies and energy difference between valence band valleys in GeTe.