In the past few decades, the use of low dimensional structures has evolved from a basic science laboratory to a solution for both the improvement of existing electronic and optoelectronic devices and the development of new ones. In the particular case of devices based on nanostructured III-V semiconductor materials such as lasers, LEDs, and photodetectors, their improved performance has been extensively demonstrated and they are already on the market. This is not fully the case for solar cells yet. It is true that research on solar cells has started many decades ago, but in this century, mostly due to the predicted consequences of global warming and the energetic challenge the world is facing, the field received an extra push and the investigation of potential improvement in solar energy conversion efficiency using nanostructures was only natural to be pursued. In this chapter, we discuss the use of III-V semiconductor quantum wells, quantum wires, and quantum dots as alternatives to boost the performance of solar cells.