Different magnetothermoelectric behavior in Al- and Ga-doped ZnO thin films

• The effect of magnetic field on the thermoelectric property was investigated.
• The tendencies of the |S| for AZO and GZO varying with magnetic field were observed.
• Magnetic field can decrease the |S| of AZO but increase that of GZO.

This essay mainly focuses on the influence of magnetic filed on thermoelectric properties of Al-doped ZnO (AZO) and Ga-doped ZnO (GZO) thin films. The Seebeck coefficients (S) of AZO and GZO films show opposite behavior as a function of the magnetic field intensity (B), which should be attributed to the effect of magnetic field on the effective electron number and potential barrier at grain boundary. For GZO film, with higher electron number, the influence of magnetic field on the effective electron number is the dominant factor, while more potential barriers at grain boundaries exist in AZO film due to the Al–O bond length with a higher mismatch to Zn–O bond length than the Ga–O bond length, so the effect of magnetic field on the potential barriers at grain boundaries dominates in AZO film.