Using 4-phenylthiosemicarbazide as an additive for densely
packed perovskite solar cells results in record efficiency of
12.22% with fewer imperfections
SEOUL,
South Korea, July 31,
2024 /PRNewswire/ -- Solar energy is one of
humanity's best bets against the ongoing energy crises and climate
change. With solar panels becoming an attractive energy solution,
scientists are diligently working to advance
existing photovoltaic technologies for sustainability.
Perovskites, a type of photovoltaic material, are the most
promising due to their potential for low-cost production and higher
efficiency.
In particular, tin halide perovskites (Sn-HPs) serve as powerful
alternatives to the exceptionally high-performing lead (Pb)-based
perovskites. Given that Sn is significantly less toxic to the
environment than Pb, research into Sn-HPs is a worthwhile endeavor.
Unfortunately, perovskite solar cells (PSCs) made from Sn-HPs still
face several challenges that need to be addressed. Specifically,
the rapid and disordered crystallization during production leads to
the formation of defects in the crystal structure of the perovskite
layer, which hampers conversion efficiency. Additionally, Sn-HPs
suffer from low stability and high sensitivity to moisture and
ambient conditions, limiting the overall lifetime of PSCs made from
them.
Now, a research team from Korea led by Associate Professor
Dong-Won Kang from Chung-Ang
University have found an elegant and efficient solution to these
issues. Their study was recently published in Volume 14, Issue 25
of Advanced Energy Materials on July 5, 2024and revealed that introducing
4-Phenylthiosemicarbazide (4PTSC) as an additive during the
production of Sn-HPs can boost the performance of PSCs.
Through extensive analyses and experimental comparisons between
regular Sn-HP PSCs and those containing the proposed additive, the
researchers showcased the multiple functionalities of 4PTSC as an
additive. "We purposely chose a multifunctional molecule that
acts as a coordination complex and a reducing agent, passivates
defect formation, and improves stability," explains Kang.
Since 4PTSC functions as a coordinating ligand, it can
effectively regulate the process of crystal growth. On the one
hand, the π-conjugated phenyl ring in the 4PTSC molecule promotes
preferred crystal growth orientation, minimizing the formation of
defects. Interestingly, 4PTSC also passivates any defects that do
form through the chemical coordination of 4PTSC and
SnI2. In turn, this shields the perovskite surface and
prevents uncoordinated Sn2+ and halide ions from
participating in unwanted reactions. What's more, the
–NH2 nucleophilic sites in 4PTSC further hinder
SnI2 oxidation and ion migration, improving the
stability of the PSCs.
Thanks to this powerful additive, the researchers were able to
produce PSCs with unprecedented performance. "The 4PTSC-modified
devices achieved a peak efficiency of 12.22% with an enhanced
open-circuit voltage of 0.94 V and exhibited superior long-term
stability, retaining almost 100% of the initial power conversion
efficiency, even after 500 h and about 80% after 1200 h in ambient
conditions without any encapsulation. This is different from the
marked degradation observed in control devices within the first 300
h," highlights Kang.
Given that Sn-HPs are relatively inexpensive to manufacture and
demonstrate good performance and great durability, study could pave
the way to more accessible and long-lasting solar panels. This can
help in making energy cheaper for the general population while
staying in line with current sustainability goals. "Addressing
the key challenges of Sn-HPs and significantly improving their
performance aligns with our goal of contributing to developing
efficient and sustainable renewable energy solutions, thereby
advancing green technologies and promoting a sustainable
future," concludes Kang.
Reference
Title of original paper: 4-Phenylthiosemicarbazide Molecular
Additive Engineering for Wide-Bandgap Sn Halide Perovskite Solar
Cells with a Record Efficiency Over 12.2%
Journal: Advanced Energy Materials
DOI: https://doi.org/10.1002/aenm.202401188
About Chung-Ang University
Website:
https://neweng.cau.ac.kr/index.do
Contact:
Sungki
Shin
02-820-6614
381076@email4pr.com
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SOURCE Chung-Ang University