we focus on small-scale energy harvesting based on the thermoelectric effect.Thermoelectric materials can be used to convert waste heat to electric energy via Seebeck effect. They are characterized by a dimensionless figure-of-merit ZT = S 2 σT/(κ e + κ L ), where S is the Seebeck coefficient (thermopower), σ the electrical conductivity, T the temperature, and κ e and κ L the electronic and lattice contributions to the thermal conductivity κ. [12] Figure 1 illustrates the basic principle of a conventional thermoelectric (TE) energy conversion device and the concept of a TE generator device combined with a flexible substrate. Furthermore, Figure 1c shows how the ZT value arises from the abovementioned individual components. Alloys of bismuth telluride (Bi 2 Te 3 ) and antimony telluride (Sb 2 Te 3 ) are by far the most widely used TE materials. They show high ZT values for near-room-temperature applications and have been utilized for decades in solid-state refrigeration applications. A major obstacle for the widespread utilization of Bi-Sb-Te based thermoelectrics is the low abundance of tellurium: it is among the rarest elements in the Earth's crust. Furthermore, current thermoelectric generators based on conventional TE materials such as Bi 2 Te 3 are typically inflexible solid-state devices, which would not be convenient for mobile small-scale applications. [12] Consequently, there is a significant interest in producing flexible and efficient TE generator solutions. In particular, a mechanically flexible TE generator solution integrated with light-weight and comfortable textile substrates could be an enabling platform for body-heat-based energy harvesting.Recently Lee et al. fabricated woven-yarn thermoelectric textiles by coating electrospun polyacrylonitrile nanofiber cores with n-type Bi 2 Te 3 and p-type Sb 2 Te 3 and twisting them into flexible yarns. [13] By weaving the TE-coated yarns into textiles, they were able to obtain an output power of up to 8.56 W m −2 for a temperature difference of 200 K in the textile thickness direction. Another recent study on thermoelectric fabrics utilized a completely different type of material solution, where thermoelectric PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) polymer was used to coat a polyester fabric with a solution-based method. [14] This fabric-TE device was based on p-type PEDOT:PSS only, resulting in a so-called unileg-type device that produced an output power of about 260 µW m −2 for a temperature difference of 75 K.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 Al 2 O 3 seed layer. The thermoelectric properties of the ZnO and ZnO-organic superlattice coatings are comp...