| 1. |
- Xiong, Shaobing, et al.
(author)
-
Reducing nonradiative recombination for highly efficient inverted perovskite solar cells via a synergistic bimolecular interface
- 2024
-
In: Nature Communications. - : NATURE PORTFOLIO. - 2041-1723. ; 15:1
-
Journal article (peer-reviewed)abstract
- Reducing interface nonradiative recombination is important for realizing highly efficient perovskite solar cells. In this work, we develop a synergistic bimolecular interlayer (SBI) strategy via 4-methoxyphenylphosphonic acid (MPA) and 2-phenylethylammonium iodide (PEAI) to functionalize the perovskite interface. MPA induces an in-situ chemical reaction at the perovskite surface via forming strong P-O-Pb covalent bonds that diminish the surface defect density and upshift the surface Fermi level. PEAI further creates an additional negative surface dipole so that a more n-type perovskite surface is constructed, which enhances electron extraction at the top interface. With this cooperative surface treatment, we greatly minimize interface nonradiative recombination through both enhanced defect passivation and improved energetics. The resulting p-i-n device achieves a stabilized power conversion efficiency of 25.53% and one of the smallest nonradiative recombination induced Voc loss of only 59 mV reported to date. We also obtain a certified efficiency of 25.05%. This work sheds light on the synergistic interface engineering for further improvement of perovskite solar cells. Reducing interface nonradiative recombination is important for realizing highly efficient perovskite solar cells. Here, the authors employ a bimolecular interlayer to functionalize the perovskite interface, achieving cooperative surface treatment and certified power conversion efficiency of 25.05%.
|
|
| 2. |
- Xiong, Shaobing, et al.
(author)
-
Revealing buried heterointerface energetics towards highly efficient perovskite solar cells
- 2023
-
In: Nano Energy. - : ELSEVIER. - 2211-2855 .- 2211-3282. ; 109
-
Journal article (peer-reviewed)abstract
- The heterointerfaces of charge-selective contacts are crucial in determining efficiency and stability of perovskite optoelectronic devices, where the fundamental knowledge of the buried heterointerface between perovskite and bottom charge transport layer is less well understood compared to the top interface. Herein, we systematically investigate the energetics at the perovskite/SnO2 buried heterointerface for an n-i-p perovskite solar cell (PSC) and the perovskite/PEDOT:PSS buried heterointerface for a p-i-n one, respectively. In contrast to previous cognitions, we discover a perovskite transition phase at the buried interface region that originates from the chemical bonding interaction with the bottom charge transport layer. The transition phase causes an energy level barrier and induces defects, impeding charge transport across the heterointerface. These detrimental effects trigger significant nonradiative recombination and limit the attainable device photovoltage. We then develop the energetic models that describe such buried heterointerfaces. Moreover, we further test the proposed model -derived mechanisms via inserting a thin polyvinyl alcohol layer into the buried heterointerfaces of the de-vices. We demonstrate that chemical interactions and formation of the perovskite transition phase at the buried heterointerface thereby are fully restrained, leading to a diminished electron extraction barrier and improved charge transport. As a result, significant increases in open-circuit voltage and fill factor of the devices are ach-ieved. These results will help guide future efforts on developing suitable buried heterointerfaces for superior performance of perovskite optoelectronics.
|
|
