CuIn1-xGax(Se,S)2 (CIGSSe) chalcopyrites have already demonstrated their potential for the indiustrial implementation of a photovoltaic technology, having reached record efficiencies around 16% in large area modules (cell 20.9% at the laboratory scale). However, involvement of scarce elements as In has been identified as a potential drawback that could limit mass deployment of these technologies. This, as well as concerns related to price of scarec elements, has motivated an increasing interest in alternative chalcogenides formed by earth abundant elements with very low toxicity. In this sense, these last five years the CIGS scientific community has began working on kesterites Cu2ZnSn(S,Se)4 (CZTS). Kesterites are compounds that present significant structural and optoelectronic similarities with CIGS, thus allowing transposing the same cell structure (glass/Mo/absorber/CdS/i-ZnO/TCO) technology directly to CZTS. However, although CZTS can inherit most of the CIGS acquired knowledge, this needs to be adapted to the particularities of the material. One of the most relevant differences is the much narrower thermodynamic region of existence of the single phase quaternary compound that has been determined for CZTS(e) at the typical growth temperatures of about 550ºC [1]. As a consequence, important drawbacks related to the coexistence of secondary phases along with the main CZTS(e) phase can be expected. Moreover, the best performing devices rely on absorbers that are Cu-poor and Zn-rich in their final composition. This leads inevitably to the formation of secondary phases [2], most likely Zn(S,Se). Another critical point that has also been recently reported remains on the widely used Mo back contacts for CIGS solar cells, which have shown being the source of a degradation of the CZTS at the region close to the interface with the back Mo contact upon thermal annealing [3] inducing the formation of the related CZTS binaries and MoS2. Another crucial tuning point still to be achieved is related to the optimization of the CZTS cell structure, which requires for an improvement of the band alignment in the heterojunction, and involves optimization of the growth of the CdS buffer layer. In this presentation we will review several strategies we are developing and investigating to address some of the above cited major issues on this material synthesized by a physical vapor deposition methods. In particular we will present several methods to improve the absorber by selectively removing undesired secondary phases [4,5], the improvement of the absorber/back contact interface by inserting a thin ZnO layer [6], and the optimization of the buffer and window layers [7], with the objective to achieve higher cell efficiencies.