Solution-processable pyrite FeS(2) nanocrystals for the fabrication of heterojunction photodiodes with visible to NIR photodetection.

A heterojunction photodiode with NIR photoresponse using solution processable pyrite FeS(2) nanocrystal ink is demonstrated which has the advantages of earth-abundance and non-toxicity. The device consists of a FeS(2) nanocrystal (NC) thin film sandwiched with semiconducting metal oxides with a structure of ITO/ZnO/FeS(2) NC/MoO(3) /Au, which exhibits an excellent photoresponse with a spectral response extended to NIR wavelengths of up to 1150 nm and a high photocurrent/dark current ratio of up to 8000 at -1 V under AM1.5 illumination (100 mW cm(-2) ).