03 July 2012 ICFO in Nature Photonics

A schematic of the bulk nanoheterojunction solar cell structure based on two types of colloidal nanocrystals

Researchers led by Gerasimos Konstantatos present a novel architectural platform for inorganic solution-processed optoelectronics and solar cells. The paper presents a bulk nano-heterojunction (BNH) platform easily implemented by mixing different semiconductor nanocrystals in solution. The device may significantly improve the performance of solar cells and allow for the development of other optoelectronic nanocomposite materials with tailored optoelectronic properties.

The authors show that the formation of a BNH can augment the carrier lifetime in a semiconductor nanomaterial, allowing efficient charge separation and transport. To achieve this, they used PbS quantum dots as the p-type component and Bi2S3 nanocrystals as the n-type semiconductor. These devices are fabricated at low temperatures (up to 100 °C), which is of great importance for low-cost, large-scale manufacturing based on roll-to-roll processing.

The paper titled Solution-processed inorganic bulk nano-heterojunctions and their application to solar cells has been published in Nature Photonics by ICFO postdoctoral researchers Arup K. Rath, and Maria Bernechea; PhD students Pelayo García de Arquer and Luis Martinez; and research engineer Johann Osmond, all led by Prof. Gerasimos Konstantatos, Nest Fellow and leader at ICFO of the Solution-processed nanophotonic devices group.