Recognizing the need for less toxic materials, our research has expanded to lead-free perovskite compositions. We strive to develop material alternatives that are both environmentally friendly and technologically viable. This is achieved by unraveling similarities of nucleation and growth processes to more studied nanocrystalline systems. Additionally, our efforts are directed towards synthesizing colloidal heterostructures with built-in interfaces based on the unique 2D geometry of nanoplates. These interfaces have a significant influence on the electronic structure and, consequently, affect device functionality, efficiency, and stability. Our ongoing studies aim to develop methods to create perovskite heterostructures and interfaces in a controlled manner, enabling us to characterize their properties at length scales critical for their practical applications.