## 1 Introduction  
Over the past decades, the advancement in the field of thin films technology paved the road for development of various semiconductor-based devices [1, 2, 3]. In this context, zinc oxide (ZnO) thin films and nanostructures attracted a great interest, owing to their unique properties such as large exciton binding energy (60 meV), direct wide-bang gap of about 3.37 eV at room temperature, high optical transparency in the visible region, low electrical resistivity, as well as high electrochemical stability, high electron mobility, non-toxicity, and abundance in nature, therefore being used in a wide range of application in the UV region of optoelectronic devices [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]. Moreover, ZnO-based nanomaterials can be considered as promising candidates for solar cells, gas sensors, laser diodes, and so on. ZnO films can be grown by several physical and chemical methods such as sputtering, chemical vapor deposition, sol-gel method, molecular beam epitaxy, and pulsed laser deposition on a wide range of substrates [14, 15, 16, 17, 18]. Taking into consideration all these approaches, in the present context of using green technologies, not all techniques are considered clean, especially wet-chemical methods for which the chemical residues involved proved to be harmful. Thus, new approaches should be considered and refined. Laser ablation has been a well-studied techniques since its early days and it has been showing the premises to be implemented for the production of n-type ZnO thin films. Pulsed laser deposition (PLD) has been studied and employed as a relatively simple and reliable technique for depositing a wide range of materials for novel applications [18, 19, 20, 21, 22, 23]. Due to its versatility, flexibility, and process speed, the technique hasemerged as a suitable production method for almost any material, ranging from simple materials (metals, oxides, semiconductors) to complex multilayer and multicomponent compounds and even biological materials with stoichiometric transfer of materials from the target [17; 18; 19; 20; 21]. Being a physical vapor deposition process that can be carried out in high vacuum, atmosphere, and even in liquids, the technique has attracted high interest in many fields. Among other advantages, the PLD technique offers the possibility of producing good quality transparent films [22; 23]. Excimer lasers represent one of the most popular gas-based lasers, generating intense short pulses in the ultraviolet spectrum. During the last decades, they have undergone rapid technological advancement, becoming one of the most utilized tools for the deposition of thin film nanomaterials. One of the biggest advantages of excimer lasers is represented by the very high gain excimer medium that can provide an adequate output for various applications that cover a broad range of applications from research to medical and even industrial ones. Excimer lasers have the ability to produce a wide range of processing power with variable repetition rates. The most often used emission lines of excimer lasers are 193 nm (ArF) and 248 nm (KrF) due to the ability of reaching high pulse energies (hundreds of mJ and even more) with high frequencies (1-50 Hz). Shot-to-shot stability is critical in PLD because it facilitates the reproducibility and stoichiometry of the thin film materials. Ceramic pre-ionization technology, part of the excimer laser, provides superior pulse-to-pulse stability at high pulse energy and adjustable depletion rates. For PLD, a high pulse energy laser fluence is imperative to vaporize any bulk material, making excimer lasers suitable for the high-precision deposition of nanostructured materials. It is well established that pure undoped ZnO films generally indicate \(n\)-type conduction. Silicon is a suitable material for integration in optoelectronic devices due to its low cost.