PbSe quantum dot solar cells based on directly synthesized semiconductive inks

The unstable PbSe quantum dot (QD) surface requires tedious and complicated synthetic protocols and renders them substantially underdeveloped compared to PbS QDs. Here, we describe a direct synthesis of PbSe QD inks at room temperature. In comparison to the conventional three-step synthesis, our strategy simplifies the fabrication process to one step and reduces the preparation cost by a factor of eight. A photovoltaic device based on these PbSe QD inks has achieved a photovoltaic conversion efficiency (PCE) of 10.38% with high device stability, which is one of the highest PCEs for all reported PbSe QD solar cells. More importantly, the obtained ink has demonstrated the best colloidal stability by far compared with all the reported lead chalcogenides (PbX) QD inks for photovoltaic application. This simple and low-cost synthesis will facilitate ink storage and transport and may ignite a new round of research efforts on the optoelectronic applications of PbSe QDs.