Nonlinear and electro-optic devices are present in our daily life with many applications: light sources for microsurgery, green laser pointers, or modulators for telecommunication. Most of them use bulk materials such as glass fibres or high-quality crystals, hardly integrable or scalable. Even the fast developments of thin film lithium niobate face the challenging etching of metal-oxides. Therefore, the quest for a non-centrosymmetric material system, easy to fabricate and to scale up while maintaining its functionality is still ongoing. Here we will present our recent advances on bottom-up photonic assemblies of randomly oriented nanocrystals and how we can produce electro-optic, nonlinear and parametric down conversion signals. First, barium titanate metalenses synthesized by a sol-gel technique will be demonstrated. Then, we will show how the electro-optic response in assembled nanostructures can be as strong as certain other perfect crystalline structure. Finally, we will generate photon pairs from free-standing lithium niobate microcubes and III-V nanowires at the telecommunication wavelength through the spontaneous parametric down-conversion process.