2 research outputs found
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
An Investigation into the Hydrogen Storage Characteristics of Ca(BH<sub>4</sub>)<sub>2</sub>/LiNH<sub>2</sub> and Ca(BH<sub>4</sub>)<sub>2</sub>/NaNH<sub>2</sub>: Evidence of Intramolecular Destabilization
We report a study of the hydrogen
storage properties of materials that result from ball milling CaÂ(BH<sub>4</sub>)<sub>2</sub> and MNH<sub>2</sub> (M = Li or Na) in a 1:1
molar ratio. The reaction products were examined experimentally by
powder X-ray diffraction, thermogravimetric analysis and differential
scanning calorimetry (TGA/DSC), simultaneous thermogravimetric modulated
beam mass spectrometry (STMBMS), and temperature-programmed desorption
(TPD). The CaÂ(BH<sub>4</sub>)/LiNH<sub>2</sub> system produces a single
crystalline compound assigned to LiCaÂ(BH<sub>4</sub>)<sub>2</sub>(NH<sub>2</sub>). In contrast, ball milling of the CaÂ(BH<sub>4</sub>)/NaNH<sub>2</sub> system leads to a mixture of NaBH<sub>4</sub> and CaÂ(NH<sub>2</sub>)<sub>2</sub> produced by a metathesis reaction and another
phase we assign to NaCaÂ(BH<sub>4</sub>)<sub>2</sub>(NH<sub>2</sub>). Hydrogen desorption from the LiCaÂ(BH<sub>4</sub>)<sub>2</sub>(NH<sub>2</sub>) compound starts around 150 °C, which is more than 160
°C lower than that from pure CaÂ(BH<sub>4</sub>)<sub>2</sub>.
Hydrogen is the major gaseous species released from these materials;
however various amounts of ammonia form as well. A comparison of the
TGA/DSC, STMBMS, and TPD data suggests that the amount of NH<sub>3</sub> released is lower when the desorption reaction is performed in a
closed vessel. There is no evidence for diborane (B<sub>2</sub>H<sub>6</sub>) release from LiCaÂ(BH<sub>4</sub>)<sub>2</sub>(NH<sub>2</sub>), but traces of other volatile boron–nitrogen species (B<sub>2</sub>N<sub>2</sub>H<sub>4</sub> and BN<sub>3</sub>H<sub>3</sub>) are observed at 0.3 mol % of hydrogen released. Theoretical investigations
of the possible crystal structures and detailed phase diagrams of
the Li–Ca–B–N–H system were conducted
using the prototype electrostatic ground state (PEGS) method and multiple
gas canonical linear programming (MGCLP) approaches. The theory is
in qualitative agreement with the experiments and explains how ammonia
desorption in a closed volume can be suppressed. The reduced hydrogen
desorption temperature of LiCaÂ(BH<sub>4</sub>)<sub>2</sub>(NH<sub>2</sub>) relative to CaÂ(BH<sub>4</sub>)<sub>2</sub> is believed to
originate from intramolecular destabilization