I’ve heard about hybrid cars, hybrid buses, even hybrid refrigerators, but hybrid solar cells are a new one. No they do not partially run on diesel or gasoline. They do, however, attempt to combine two traditionally separate solar cell materials in order to maximize efficiency and output. These new composite materials, as developed by the Instituto Madrileno de Estudios Avanzados en Nanosciencia (IMDEA Nanoscience), is based on semiconductor nanoparticles and carbon nanotubes.

Semiconductor nanocrystals, or quantum dots, have a broad absorption spectrum (they can be manipulated from ultraviolet to near infrared) and can be covered by extremely thin layers of other semiconductor materials to improve stability and luminescent properties. All that basically means that these nanoparticles are relatively easy to work with for PV researchers. As evidence of that fact, thin-film solar cell producers increasingly use nanoparticles such as Cadmium-Telluride. In other words, nanocrystalline solar cells are no stranger to the PV market.

These solar cells do have one drawback: they are fragile. In response, they are covered with an organic shell for protection and to keep them stable in non-polar organic solvents. These shells, while beneficial in terms of protection and thus efficiency, inhibit electrical conduction.

Enter carbon nanotubes. Carbon nanotubes consist of rolled up graphene layers. They can be single-wall (just one layer) and multi-wall. These nanotubes, as opposed to the organic shells discussed above, have highly conductive properties. What scientists at IMDEA are developing is a hybrid solar cell that would combine the high efficiency of nanocrystalline semiconductors with the high electrical conductivity of carbon nanotubes.

This research is still in the very early stages. Nonetheless, initial tests show substantial promise.

Via Science Daily

Posted on November 28th in Solar News by Dan.