Electronic structure of Sn(1-x)Mn(x)Te semiconducting solid solution: a resonant photoemission study

TL;DR

This study investigates how manganese doping alters the electronic structure of SnTe, revealing changes in valence band states and potential implications for thermoelectric performance, using resonant photoemission spectroscopy.

Contribution

It provides detailed insights into the electronic band structure modifications in Mn-doped SnTe, highlighting the role of Mn3d electrons and valence band renormalization.

Findings

Mn3d electrons contribute at the valence band edge and 4 eV maximum.

Strong renormalization of Sn5p and Te5p states observed.

Altered valence band shape influences electron effective mass.

Abstract

Manganese-doped tin telluride, Sn(1-x)Mn(x)Te, initially investigated as diluted magnetic semiconductor, has recently attracted considerable attention as a prospective thermoelectric material. The introduction of Mn was found to modify the valence band electronic structure, resulting in an improvement in the Seebeck coefficient and thus, the figure of merit (ZT). In the paper, we present a synchrotron radiation study of the electronic band structure of Sn(0.9)Mn(0.1)Te by resonant photoemission. The contribution of the Mn3d electrons to the valence band (VB), calculated as the difference between the Energy Distribution Curves (EDCs) taken at the maximum and minimum of the Fano resonance for the Mn3p - Mn3d absorption threshold, shows a contribution at the VB edge, a dominant maximum at 4 eV, as well as a wide structure between 7 and 11 eV. Moreover, comparison with undoped SnTe reveals strong renormalization of the Sn5p and Te5p electronic states, which certainly influences the shape of the upper part of the valence band and electron effective mass.