Colloidal quantum dots(CQDs), especially lead chalcogenide CQDs, are regarded as promising materials for the next generation solar cells, due to their large absorption coefficient, excellent charge transport,and multiple exciton generation effect. We successfully synthesized highly-crystalline, monodispersed,well-alloyed PbS_xTe_(1-x) nanocrystals via a one-pot, hot injection reaction method. Energy-filtered transmission electron microscopy suggested that the S and Te anions were uniformly distributed in the alloy nanoparticles. The photovoltaic performance of CQD solar cells based on ternary PbS_xTe_(1-x) was reported for the first time. The photovoltaic devices using PbS_xTe_(1-x) were more efficient than either the pure PbS or the PbTe based devices. In addition, the PbS_xTe_(1-x) based devices showed a significantly improved stability than that of the PbTe based devices.
Xiangxiang ZhuZeke LiuGuozheng ShiJinan GuWeiwei WangWanli Ma
Colloidal zinc oxide(ZnO) nanocrystals generated from the high temperature and nonaqueous approache are attractive for use in solution-processed electrical and optoelectronic devices. However, the asprepared colloidal ZnO nanocrystals by this approach are generally capped by ligands with long alkyl-chains,which is disadvantage for solution-processed devices due to hindering charge transport. Here we demonstrate an effective ligand exchange process for the colloidal ZnO nanocrystals from the high temperature and nonaqueous approach by using n-butylamine. The ligand exchange process was carefully characterized. The thin films based on colloidal ZnO nanocrystals after ligand exchange exhibited dramatically enhanced UV photoconductivity.
Jun LuoXingliang DaiSai BaiYizheng JinZhizhen YeXiao jun Guo
