Nanoengineering approach has been applied to Al-doped ZnO (AZO thin films prepared by different techniques, with the purpose of enhancing their thermoelectric performance.

The insertion of artificial nanodefects into the AZO matrix has been considered with the aim of depressing the thermal conductivity (κ) and enhancing the figure of merit (ZT).

Several approaches have been tried:

1. insertion of hydroquinone nanolayers in AZO films prepared by atomic layer deposition (ALD): κ_ALD (300 K) = 3.56 W m^-1 K^-1;
2. addition of polymetylmetacrilate (PMMA) particles to AZO films prepared by multi-beam multitarget matrix-assisted pulsed laser deposition (MBMT/MAPLE-PLD): κ_MAPLE (300 K) = 5.9 W m^-1 K^-1;
3. formation of nanopores in AZO films prepared by Mist-Chemical Vapor Deposition (Mist-CVD): κ _porous (300 K) = 0.60 W m^-1 K^-1;
4. dispersion of Al2O3 nanoparticulate in AZO films prepared by surface-modified target pulsed laser deposition: κ_nanoAl2O3 (300 K) = 3.98 W m^-1 K^-1.

All these examples highlight the promise of thermoelectric nanostructured AZO thin films for future heat harvesting applications