3 research outputs found
Chiral Perovskite Nanocrystal Growth inside Helical Hollow Silica Nanoribbons
Helical
perovskite nanocrystals (H-PNCs) were prepared using nanometric
silica helical ribbons as platforms for the in situ growth of the
crystals using the supersaturated recrystallization method. The H-PNCs
grow inside nanometric helical porous silica, and their handedness
is determined by the handedness of porous silica templates. They show
both strong induced circular dichroism (CD) and strong induced circularly
polarized luminescence (CPL) signals, with high dissymmetry g-factors.
Right-handed and left-handed PNCs show respectively positive and negative
CD and CPL signals, with a dissymmetry g-factor (abs and lum) of ∼±2
× 10–2. Simulations based on the boundary element
method demonstrate that the circular dichroism originates from the
chiral shape of H-PNCs
Micrometer-Size Vesicle Formation Triggered by UV Light
Vesicle
formation is a fundamental kinetic process related to the
vesicle budding and endocytosis in a cell. In the vesicle formation
by artificial means, transformation of lamellar lipid aggregates into
spherical architectures is a key process and known to be prompted
by e.g. heat, infrared irradiation, and alternating electric field
induction. Here we report UV-light-driven formation of vesicles from
particles consisting of crumpled phospholipid multilayer membranes
involving a photoactive amphiphilic compound composed of 1,4-bisÂ(4-phenylethynyl)Âbenzene
(BPEB) units. The particles can readily be prepared from a mixture
of these components, which is casted on the glass surface followed
by addition of water under ultrasonic radiation. Interestingly, upon
irradiation with UV light, micrometer-size vesicles were generated
from the particles. Neither infrared light irradiation nor heating
prompted the vesicle formation. Taking advantage of the benefits of
light, we successfully demonstrated micrometer-scale spatiotemporal
control of single vesicle formation. It is also revealed that the
BPEB units in the amphiphile are essential for this phenomenon
Efficient and Stable Carbon-Based Perovskite Solar Cells Enabled by Mixed CuPc:CuSCN Hole Transporting Layer for Indoor Applications
Perovskite solar cells (PSCs) are an innovative technology
with
great potential to offer cost-effective and high-performance devices
for converting light into electricity that can be used for both outdoor
and indoor applications. In this study, a novel hole-transporting
layer (HTL) was created by mixing copper phthalocyanine (CuPc) molecules
into a copper(I) thiocyanate (CuSCN) film and was applied to carbon-based
PSCs with cesium/formamidinium (Cs0.17FA0.83Pb(I0.83Br0.17)3) as a photoabsorber.
At the optimum concentration, a high power conversion efficiency (PCE)
of 15.01% was achieved under AM1.5G test conditions, and 32.1% PCE
was acquired under low-light 1000 lux conditions. It was discovered
that the mixed CuPc:CuSCN HTL helps reduce trap density and improve
the perovskite/HTL interface as well as the HTL/carbon interface.
Moreover, the PSCs based on the mixed CuPc:CuSCN HTL provided better
stability over 1 year due to the hydrophobicity of CuPc material.
In addition, thermal stability was tested at 85 °C and the devices
achieved an average efficiency drop of approximately 50% of the initial
PCE value after 1000 h. UV light stability was also examined, and
the results revealed that the average efficiency drop of 40% of the
initial value for 70 min of exposure was observed. The work presented
here represents an important step toward the practical implementation
of the PSC as it paves the way for the development of cost-effective,
stable, yet high-performance PSCs for both outdoor and indoor applications