In this chapter, two promising solar cell technologies are presented-namely, hot carrier solar cells and solution-processable, quantum dot solar cells. These technologies have the potential to reduce the per-watt generation cost of electricity. Hot carrier solar cells can achieve this, as they have very high efficiency and promote the use of thin-film technologies. On the other hand, the material and fabrication costs of solution-processable, quantum dot solar cells are very low. This discussion gives an overview of these technologies and the development in these fields.