Quantum Dot Solar Cell

Quantum Dot Solar Cell

Quantum dot solar cells are an emerging field in solar cell research that uses quantum dots as the photovoltaic material, as opposed to better-known bulk materials such as silicon, copper indium gallium selenide (CIGS) or CdTe. Quantum dots have bandgaps that are tunable across a wide range of energy levels by changing the quantum dot size. This is in contrast to bulk materials, where the bandgap is fixed by the choice of material composition. This property makes quantum dots attractive for multi-junction solar cells, where a variety of different energy levels are used to extract more power from the solar spectrum.

The potential performance of the quantum dot approach has led to widespread research in the field. Early examples used costly molecular beam epitaxy processes, but alternative inexpensive fabrication methods have been developed. These attempts rely on quantum dot synthesis using wet chemistry (colloidal quantum dots – CQDs) and subsequent solution processibility of quantum dots. Recent efforts have also used successive ionic layer absorption and reaction (SILAR) for semiconductor deposition. Their efficiency of 7.0% is among the highest observed for QDSCs and, although quite low compared to that of commercial bulk silicon cells (about 17%), it has a potential for improvement beyond silicon cells.