It has been widely demonstrated that pulsed-laser deposition (PLD) based on the process of the transportation of a material (laser ablation) is a successful technique for the growth of
stoichiometric multicomponent oxide films [1,2]. Indeed, PLD has shown unique advantages for the formation of dense films for energy storage and conversion, namely a high reproducibility, easy control of the growth rate, and a high film purity with a variety of substrates, such as amorphous glass, oriented silicon [3], stainless steel [4], (001)Al₂O₃ [5], indium tin oxide (ITO)- and ZnO-coated glass, and ITO-coated Upilex polymer [6].

Generally, the stoichiometry of the target phase is preserved in PLD films of oxides but a deviation is observed for lithiated material that implies an Li-enriched target. Consequently, the loss of volatile Li during deposition is compensated for by using about a 15 wt. % excess of Li₂O [7,8]. Accurate stoichiometry can be obtained by controlling several parameters of the process. The typical set-up for the fabrication of PLD films consists of a stainless-steel vacuum chamber evacuated down to a residual pressure less than 1 × 10⁻⁴ Pa before material deposition. Energy (laser fluence) in the range of 1.0 to 3.0 J·cm⁻² is generated by a pulsed-laser beam, which falls onto the target surface with an incidence angle of approximately 45° (see Table 1 for laser characteristics). Indeed, four PLD parameters are of prime importance for the growth of films: The laser fluence; type of substrate; orientation and lattice parameters, which must match with those of the film for an efficient epitaxy process; substrate temperature (Ts); and the oxygen partial pressure (pO₂). In addition, as the capacity of the microbattery depends on the electrode thickness, the duration of the deposition (tp) must also be considered. The activity of a thin-film electrode, i.e., specific discharge energy, is proportional to the thickness, thus an increase of the film thickness leads to a power limitation because of the slow transport kinetic of Li⁺ ions.

Consequently, PLD is a popular technique due to the growth of a compact and dense film, which is replaced by a thick and porous film. Another advantage of the physical vacuum-like deposition techniques is the possibility of depositing a thin layer on top of the microbattery, which protects the device against a reactivity toward moisture. Moreover, due to the well-defined surface area of PLD films, a direct comparison of the electrochemical activity of materials can be done for different morphologies, from amorphous to single-crystalline materials [9].