Flexible Thermoelectric ZnO-Organic Superlattices on Cotton Textile Substrates by ALD/MLD

Abstract

The thermoelectric properties of both pristine ZnO and ZnO-organic superlattice thin films deposited on a cotton textile are investigated. The thin films are fabricated by atomic layer deposition/molecular layer deposition, using hydroquinone as the organic precursor for the superlattices. The resulting thin-film coatings are crystalline, in particular when deposited on a textile substrate with a thin predeposited Al2O3 seed layer. The thermoelectric properties of the ZnO and ZnO-organic superlattice coatings are comparable to those for thin films deposited on conventional inorganic substrates; Al doping can be employed to further improve the thermoelectric properties. The ZnO-organic superlattice thin films moreover show enhanced resistance to mechanical strain. Due to the higher flexibility and lower thermal conductivity in comparison to pristine ZnO thin films, the ZnO-organic superlattice thin films are a possible material platform for flexible thermoelectrics that can be integrated in textiles and applied in wearable electronics.