Publication

Single-step colloidal quantum dot films for infrared solar harvesting

​Single-step colloidal quantum dot films for infrared solar harvesting
Amirreza Kiani, Brandon R. Sutherland, Younghoon Kim, Olivier Ouellette, Larissa Levina, Grant Walters, Cao-Thang Dinh, Mengxia Liu, Oleksandr Voznyy, Xinzheng Lan, Andre J. Labelle, Alexander H. Ip, Andrew Proppe, Ghada H. Ahmed, Omar F. Mohammed, Sjoerd Hoogland and Edward H. Sargent
Appl. Phys. Lett. 109, 183105 (2016)
Amirreza Kiani, Brandon R. Sutherland, Younghoon Kim, Olivier Ouellette, Larissa Levina, Grant Walters, Cao-Thang Dinh, Mengxia Liu, Oleksandr Voznyy, Xinzheng Lan, Andre J. Labelle, Alexander H. Ip, Andrew Proppe, Ghada H. Ahmed, Omar F. Mohammed, Sjoerd
band gap, solar cells, solvents, semiconductors
2016

 

Semiconductors with bandgaps in the near- to mid-infrared can harvest solar light that is otherwise wasted by conventional single-junction solar cell architectures. In particular, colloidal quantum dots (CQDs) are promising materials since they are cost-effective, processed from solution, and have a bandgap that can be tuned into the infrared (IR) via the quantum size effect. These characteristics enable them to harvest the infrared portion of the solar spectrum to which silicon is transparent. To date, IR CQD solar cells have been made using a wasteful and complex sequential layer-by-layer process. Here, we demonstrate ∼1 eV bandgap solar-harvesting CQD films deposited in a single step. By engineering a fast-drying solvent mixture for metal iodide-capped CQDs, we deposited active layers greater than 200 nm in thickness having a mean roughness less than 1 nm. We integrated these films into infrared solar cells that are stable in air and exhibit power conversion efficiencies of 3.5% under illumination by the full solar spectrum, and 0.4% through a simulated silicon solar cell filter.

 

doi: 10.1063/1.4966217