Researchers at RTI International in North Carolina have reported in Applied Physics Letters that they have developed a new solar technology that could make solar energy more affordable.

The RTI solar cells (technically, planar PbS quantum dot/C60 heterojunction photovoltaic devices) are formed from solutions of semiconductor particles, known as colloidal quantum dots, and can have a power conversion efficiency that is competitive to traditional cells at a fraction of the cost.

The solar cells were created using low-cost materials and manufacturing techniques. The cells can be manufactured using high volume roll-to-roll processing and inexpensive coating processes, which reduces capital costs and increases production. Unlike traditional solar cells, the RTI cells can be processed at room temperature, further reducing input energy requirements and cost.

Preliminary analysis of the material costs of the technology show that it can be produced for less than $20 per square meter—as much as 75% less than traditional solar cells.