%0 Journal Article %1 doi:10.1021/acs.jpclett.7b01508 %A Hawash, Zafer %A Raga, Sonia R. %A Son, Dae-Yong %A Ono, Luis K. %A Park, Nam-Gyu %A Qi, Yabing %D 2017 %J The Journal of Physical Chemistry Letters %K energyLevelTuning interlayer perovskite %N ja %P null %R 10.1021/acs.jpclett.7b01508 %T Interfacial Modification of Perovskite Solar Cells using an Ultrathin MAI Layer Leads to Enhanced Energy Level Alignment, Efficiencies, and Reproducibility %U http://dx.doi.org/10.1021/acs.jpclett.7b01508 %V 0 %X In the past few years, organic-inorganic halide perovskites have demonstrated their particular potential for optoelectronic device applications. Exceptional performance has been already achieved in perovskite solar cells (PSCs). On the other hand, there are concerns regarding the sensitive dependence of device performance on fabrication conditions, which is expected to have a strong impact on PSCs performance and reproducibility. In this work, for the first time, we intentionally deposit a definite ultrathin layer of excess methyl ammonium iodide (MAI) on top of a methyl ammonium lead iodide (MAPI) perovskite film. Using photoelectron spectroscopy, we investigate the role of excess MAI at the interface between perovskite and spiro-MeOTAD hole transport layer in standard structure PSCs. We found that interfacial favorable energy level tuning of MAPI film can be achieved by controlling the amount of excess MAI on top of the MAPI film. The optimized interface energetics was verified by solar cell device testing, leading to both an increase of 19\% in average steady state PCE (from 14.5\% to 17.2\%) and significantly improved reproducibility, which is represented by a much lower PCE standard deviation of 0.4\% and 1.9\%, respectively.

@article{doi:10.1021/acs.jpclett.7b01508, abstract = { In the past few years, organic-inorganic halide perovskites have demonstrated their particular potential for optoelectronic device applications. Exceptional performance has been already achieved in perovskite solar cells (PSCs). On the other hand, there are concerns regarding the sensitive dependence of device performance on fabrication conditions, which is expected to have a strong impact on PSCs performance and reproducibility. In this work, for the first time, we intentionally deposit a definite ultrathin layer of excess methyl ammonium iodide (MAI) on top of a methyl ammonium lead iodide (MAPI) perovskite film. Using photoelectron spectroscopy, we investigate the role of excess MAI at the interface between perovskite and spiro-MeOTAD hole transport layer in standard structure PSCs. We found that interfacial favorable energy level tuning of MAPI film can be achieved by controlling the amount of excess MAI on top of the MAPI film. The optimized interface energetics was verified by solar cell device testing, leading to both an increase of 19\% in average steady state PCE (from 14.5\% to 17.2\%) and significantly improved reproducibility, which is represented by a much lower PCE standard deviation of 0.4\% and 1.9\%, respectively. }, added-at = {2017-08-08T07:37:35.000+0200}, author = {Hawash, Zafer and Raga, Sonia R. and Son, Dae-Yong and Ono, Luis K. and Park, Nam-Gyu and Qi, Yabing}, biburl = {https://www.bibsonomy.org/bibtex/2822626465df4972b0f68e071636ed120/cgoehler}, description = {acs.jpclett.7b01508}, doi = {10.1021/acs.jpclett.7b01508}, eprint = {http://dx.doi.org/10.1021/acs.jpclett.7b01508}, interhash = {8c7aa6fd51c00d775c5b2016a6299c4b}, intrahash = {822626465df4972b0f68e071636ed120}, journal = {The Journal of Physical Chemistry Letters}, keywords = {energyLevelTuning interlayer perovskite}, note = {PMID: 28767259}, number = {ja}, pages = {null}, timestamp = {2017-08-08T07:37:35.000+0200}, title = {Interfacial Modification of Perovskite Solar Cells using an Ultrathin MAI Layer Leads to Enhanced Energy Level Alignment, Efficiencies, and Reproducibility}, url = {http://dx.doi.org/10.1021/acs.jpclett.7b01508}, volume = 0, year = 2017 }