Quantum dot solar cell

A quantum dot solar cell (QDSC) is a solar cell design that uses quantum dots as the captivating photovoltaic material. It attempts to replace bulk materials such as silicon, copper indium gallium selenide (CIGS) or cadmium telluride (CdTe). Quantum dots have bandgaps that are adjustable across a wide range of energy levels by changing their size. In bulk materials, the bandgap is fixed by the choice of material(s).^[1] This property makes quantum dots attractive for multi-junction solar cells, where a variety of materials are used to improve efficiency by harvesting multiple portions of the solar spectrum.^[2]

As of 2022, efficiency exceeds 18.1%.^[3] Quantum dot solar cells have the potential to increase the maximum attainable thermodynamic conversion efficiency of solar photon conversion up to about 66% by utilizing hot photogenerated carriers to produce higher photovoltages or higher photocurrents.^[4]

Typical quantum dots solar cells consist of a glass substrate followed by a transparent electrically conducting indium tin oxide(ITO) that allows light to penetrate the solar cell. It also contains a conducting polymer, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), to enroll as electron blocker and hole injector to the ITO layer. Finally, quantum dots(QDs) such as cadmium selenide along with poly(3-hexylthiophene) (P3HT) are used between the metal cathode and the conductive polymer layer to ensure optimal function.^[5]