The hypothesis of a massive spread of “green” energy systems based on renewables has recently started to raise some concerns, regarding the dependence of several of those technologies on critical raw materials. There are serious doubts if the number of materials available to meet the demands of the different renewable and storage technologies is sufficient. As tempting as it is to completely replace these critical materials with more common ones, this approach requires fundamental and technological optimization that will take a considerable amount of time and resources. In this work, through different interface passivation and light management schemes, we show that thin film solar cells of (Ag)Cu(In,Ga)Se2 – (A)CIGS – might have a four-fold reduction in the use of its materials, to an ultrathin architecture, decreasing significantly the used amount of Ag, In, and Ga. Nevertheless, as the thickness of the absorber is scaled down, new challenges appear: higher influence of rear interface recombination on the device performance, as well as incomplete light absorption. In this work, we present and discuss different rear nanocontact architectures for interface passivation via the inclusion of different dielectric materials, and rear light management schemes involving metallic and dielectric nanostructures for scattering to enhance the optical path length in the absorber, as well as omnidirectional anti-refection approaches for the solar cell front surface based on the effective medium theory. Each aforementioned strategy leads to improvements in the absolute light to power conversion efficiency value that can be up to 2 % and when incorporated together then can increase the device performance by 6 %.