Random band-edge model description of thermoelectricity in high-mobility disordered semiconductors : Application to the amorphous oxide In-Ga-Zn-O

Title data

Fishchuk, Ivan I. ; Kadashchuk, Andrey ; Rolin, Cedric ; Bässler, Heinz ; Köhler, Anna ; Heremans, Paul ; Genoe, Jan:
Random band-edge model description of thermoelectricity in high-mobility disordered semiconductors : Application to the amorphous oxide In-Ga-Zn-O.
In: Physical Review B. Vol. 105 (2022) Issue 24 . - 245201.
ISSN 0163-1829
DOI: https://doi.org/10.1103/PhysRevB.105.245201

Official URL:

Abstract in another language

Unraveling the dominant charge transport mechanism in high-mobility amorphous oxide semiconductors is still a matter of controversy. In the present study we extended the random band-edge model suggested before for the charge transport and Hall-effect mobility in such disordered materials [Fishchuk et al., Phys. Rev. B 93, 195204 (2016)], and also describe the field-effect-modulated thermoelectricity in amorphous In-Ga-Zn-O (a-IGZO) films under the same premises. The model is based on the concept of charge transport through the extended states and assumes that the transport is limited by the spatial variation of the position of the band edge due to the disorder potential, rather than by localized states. The theoretical model is formulated using the effective medium approximation framework and describes well basic features of the Seebeck coefficient in disordered materials as a function of energy disorder, carrier concentration, and temperature. Carrier concentration dependencies of power factor and thermoelectric figure of merit have been also considered for such systems. Besides, our calculations reveal a remarkable turnover effect from a negative to a positive temperature dependence of Seebeck coefficient upon increasing carrier concentration. The suggested unified model provides a good quantitative description of available experimental data on the Seebeck coefficient and the charge mobilities measured in the same a-IGZO transistor as a function of the gate voltage and temperature by considering the same charge transport mechanisms. This promotes a deeper understanding and a more credible and accurate description of the transport process in a-IGZO films.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Institutions of the University:	Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics II - Optoelectronics of Soft Matter Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics II - Optoelectronics of Soft Matter > Chair Experimental Physics II - Optoelectronics of Soft Matter - Univ.-Prof. Dr. Anna Köhler Faculties Faculties > Faculty of Mathematics, Physics und Computer Science
Result of work at the UBT:	Yes
DDC Subjects:	500 Science > 530 Physics
Date Deposited:	13 Jun 2023 07:24
Last Modified:	15 Aug 2023 06:55
URI:	https://eref.uni-bayreuth.de/id/eprint/81314