Layered hybrid perovskites have recently re-emerged as potential technological viable solutions for photovoltaic and optoelectronic applications. Their environmental stability and immunity to moisture coupled to their exciting optoelectronic properties, have given them a new opportunity in the search of efficient solar cell and light emitting devices1,2. This is partly due to the quantum and dielectric confinement effects that emerge through their low dimensionality3,4. Moreover, the self-assembled nature of layered perovskites confers them a huge flexibility in their structural and optoelectronic properties3. Thus, creating an interesting playground for material and device engineering. However, further insight into their unique properties requires substantial experimental and theoretical works. Hence, understanding their fundamental optical and electronic properties will be important for optimization and proposal of design guidelines to experimentalists. Here, we present some of the methods and tools we use to inspect their properties related to quantum and dielectric confinement effects4,5,6. By combining different theoretical approaches, we investigate their electronic and dielectric properties. References: 1. Tsai et al. “High-efficiency two-dimensional Ruddlesden–Popper perovskite solar cells”, Nature, vol. 536, 2016 2. Mao et al., “Tunable White-Light Emission in Single-Cation-Templated Three- Layered 2D Perovskites (CH3CH2NH3)4Pb3Br10−xClx”, J. Am. Chem. Soc., vol. 139, pp. 11956−11963, 2017 3. Katan et al., “Quantum and Dielectric Confinement Effects in Lower-Dimensional Hybrid Perovskite Semiconductors”, Chem. Rev., vol. 119, pp. 3140-3192, 2019 4. Traore et al., “Composite Nature of Layered Hybrid Perovskites: Assessment on Quantum and Dielectric Confinements and Band Alignment”, ACS Nano, vol. 12, pp. 3321–3332, 2018 5. Even et al., “Understanding Quantum Confinement of Charge Carriers in Layered 2D Hybrid Perovskites”, ChemPhysChem, vol. 15, 3733 – 3741, 2014 6. Kepenekian et al., “Concept of Lattice Mismatch and Emergence of Surface States in Two-dimensional Hybrid Perovskite Quantum Wells”, Nano Lett., vol. 18, pp. 5603-5609, 2018