Research on solution-processable semiconductors has achieved significant fundamental and technological advancements over the last decade, in large part due to improvements in characterization techniques to understand these materials at different length scales. Notable example include hybrid perovskites and organic semiconductors, which have garnered interest for a wider energy paradigm and sustainability. Recent upserge in the solar-to-enelectrical energy conversion further expands the application space for these materials. Hoever, some fundamental questions regarding to the solar cell efficiencies of are related to morphology, defects, local disorder and interfaces between the semiconductor thin films and charge transport layers. To this end, understanding structure-stability-property relationships in emerging photovoltaics brings new opportunities and challenges to characterization techniques. Synergy between length and timescales of characterization techniques is particularly important.^[1,2] We will present how local structures/morphology and interactions can be resolved by state-of-the-art magnetic resonance spectroscopy and imaging techniques at high fields.^[3-4] Specifically, recent in situ and ex situ capabilities for examining thin films at micron-to-submicron thicknesses will be discussed. Gaining access to the local interfacial structures enables a number of questions to be addressed including a better picture of stacked semiconductor layers in electronic devices, diffusion of electrodes into photo-active layers, and film formation kinetics and molecules aggregation, surfaces/bulk passivation, and instability and degradation reactions and kinetics.^[5-7]