Highly efficient air-stable colloidal quantum dot solar cells by improved surface trap passivation

Randi Azmi, Septy Sinaga, Havid Aqoma, Gabsoek Seo, Tae Kyu Ahn, Minsuk Park, Sang Yong Ju, Jin Won Lee, Tae Wook Kim, Seung Hwan Oh, Sung Yeon Jang

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31 Citations (Scopus)


While the power conversion efficiency (PCE) of colloidal quantum dot (CQD) solar cells can reach > 10%, the major obstacle for charge extraction and energy loss in such devices is the presence of surface trap sites within CQDs. In this work, highly trap-passivated PbS CQDs were developed using a novel iodide based ligand, 1-propyl-2,3-dimethylimidazolium iodide (PDMII). We examined the effects of PDMII on the surface quality of PbS-CQDs and compared them with TBAI, which is the best-selling iodide based ligand. By using PDMII, improved surface passivation with reduced sub-bandgap trap-states compared to TBAI was achieved. The reduced trap density resulted in enhanced charge extraction with diminished energy loss (0.447 eV) in the devices. Solar cell devices using our PDMII based CQDs displayed high PCE and air stability. The certified PCE of our PDMII based devices reached 10.89% and was maintained at 90% after 210 days of air storage.

Original languageEnglish
Pages (from-to)86-94
Number of pages9
JournalNano Energy
Publication statusPublished - 2017 Sep


All Science Journal Classification (ASJC) codes

  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)
  • Electrical and Electronic Engineering

Cite this

Azmi, R., Sinaga, S., Aqoma, H., Seo, G., Ahn, T. K., Park, M., Ju, S. Y., Lee, J. W., Kim, T. W., Oh, S. H., & Jang, S. Y. (2017). Highly efficient air-stable colloidal quantum dot solar cells by improved surface trap passivation. Nano Energy, 39, 86-94. https://doi.org/10.1016/j.nanoen.2017.06.040