Abstract
The electron-transport layer (ETL) between the active perovskite material and the cathode plays a critical role in planar perovskite solar cells. Herein, we report a drastically improved solar cell efficiency via surface optimization of the TiO2 ETL using a special ionic-liquid (IL) that shows high optical transparency and superior electron mobility. As a consequence, the efficiency is promoted to as high as 19.62% (the certified efficiency is 19.42%), exceeding the previous highest efficiency recorded for planar CH3NH3PbI3 perovskite solar cells. Surprisingly, the notorious hysteresis is completely eliminated, likely due to the improved ETL quality that has effectively suppressed ion migration in the perovskite layer and charge accumulation at the interfaces, higher electron mobility to balance the hole flux at the anode, and a better growth platform for the high quality perovskite absorber. Both experimental analyses and theoretical calculations reveal that the anion group of the IL bonds to TiO2, leading to a higher electron mobility and a well-matched work function. Meanwhile, the cation group interfaces with adjacent perovskite grains to provide an effective channel for electron transport and a suitable setting to grow low trap-state density perovskite for improved device performance.
| Original language | English |
|---|---|
| Pages (from-to) | 3071-3078 |
| Number of pages | 8 |
| Journal | Energy and Environmental Science |
| Volume | 9 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - Oct 1 2016 |
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ASJC Scopus subject areas
- Environmental Chemistry
- Renewable Energy, Sustainability and the Environment
- Nuclear Energy and Engineering
- Pollution
Cite this
Surface optimization to eliminate hysteresis for record efficiency planar perovskite solar cells. / Yang, Dong; Zhou, Xin; Yang, Ruixia; Yang, Zhou; Yu, Wei; Wang, Xiuli; Li, Can; Liu, Shengzhong; Chang, Robert P H.
In: Energy and Environmental Science, Vol. 9, No. 10, 01.10.2016, p. 3071-3078.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Surface optimization to eliminate hysteresis for record efficiency planar perovskite solar cells
AU - Yang, Dong
AU - Zhou, Xin
AU - Yang, Ruixia
AU - Yang, Zhou
AU - Yu, Wei
AU - Wang, Xiuli
AU - Li, Can
AU - Liu, Shengzhong
AU - Chang, Robert P H
PY - 2016/10/1
Y1 - 2016/10/1
N2 - The electron-transport layer (ETL) between the active perovskite material and the cathode plays a critical role in planar perovskite solar cells. Herein, we report a drastically improved solar cell efficiency via surface optimization of the TiO2 ETL using a special ionic-liquid (IL) that shows high optical transparency and superior electron mobility. As a consequence, the efficiency is promoted to as high as 19.62% (the certified efficiency is 19.42%), exceeding the previous highest efficiency recorded for planar CH3NH3PbI3 perovskite solar cells. Surprisingly, the notorious hysteresis is completely eliminated, likely due to the improved ETL quality that has effectively suppressed ion migration in the perovskite layer and charge accumulation at the interfaces, higher electron mobility to balance the hole flux at the anode, and a better growth platform for the high quality perovskite absorber. Both experimental analyses and theoretical calculations reveal that the anion group of the IL bonds to TiO2, leading to a higher electron mobility and a well-matched work function. Meanwhile, the cation group interfaces with adjacent perovskite grains to provide an effective channel for electron transport and a suitable setting to grow low trap-state density perovskite for improved device performance.
AB - The electron-transport layer (ETL) between the active perovskite material and the cathode plays a critical role in planar perovskite solar cells. Herein, we report a drastically improved solar cell efficiency via surface optimization of the TiO2 ETL using a special ionic-liquid (IL) that shows high optical transparency and superior electron mobility. As a consequence, the efficiency is promoted to as high as 19.62% (the certified efficiency is 19.42%), exceeding the previous highest efficiency recorded for planar CH3NH3PbI3 perovskite solar cells. Surprisingly, the notorious hysteresis is completely eliminated, likely due to the improved ETL quality that has effectively suppressed ion migration in the perovskite layer and charge accumulation at the interfaces, higher electron mobility to balance the hole flux at the anode, and a better growth platform for the high quality perovskite absorber. Both experimental analyses and theoretical calculations reveal that the anion group of the IL bonds to TiO2, leading to a higher electron mobility and a well-matched work function. Meanwhile, the cation group interfaces with adjacent perovskite grains to provide an effective channel for electron transport and a suitable setting to grow low trap-state density perovskite for improved device performance.
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U2 - 10.1039/c6ee02139e
DO - 10.1039/c6ee02139e
M3 - Article
VL - 9
SP - 3071
EP - 3078
JO - Energy and Environmental Science
JF - Energy and Environmental Science
SN - 1754-5692
IS - 10
ER -