There have been great interests in recent years on exploring the use of hybrid organic-inorganic nanostructures in various sustainable energy applications including photovoltaics and light-emitting devices (LEDs). Organic electronic materials such as conjugated polymers have advantages in low material cost, tunability in material properties, and compatibility with flexible substrate and roll-to-roll processing techniques. Colloidal inorganic nanoparticles can be processed in solutions together with polymers and potentially offer enhanced charge carrier mobility and environmental stability. In this talk I will present our recent work on using hybrid organic-inorganic nanostructures for solar cells and light-emitting devices (LEDs). We show that inclusion of a ZnO nanoparticle based electron transport layer in polymer LEDs leads to turn-on voltages significantly lower than the bandgap voltages, which is attributed to an Auger-assisted energy up-conversion process at the polymer/ZnO interface. We also demonstrated high efficiency and stable quantum dot-based LEDs using a polymer hole transport layer and a ZnO nanoparticle electron transport layer. Finally, we have significantly improved the efficiency and stability of polymer-colloidal nanocrystal solar cells using a combination of interface engineering approaches.