5 research outputs found
Efficient and Stable Large-Area Perovskite Solar Cells with Inorganic Perovskite/Carbon Quantum Dot-Graded Heterojunction
This work reports on a compositionally graded heterojunction for photovoltaic application by cooperating fluorine-doped carbon quantum dots (FCQDs in short) into the CsPbI2.5Br0.5 inorganic perovskite layer. Using this CsPbI2.5Br0.5/FCQDs graded heterojunction in conjunction with low-temperature-processed carbon electrode, a power conversion efficiency of 13.53% for 1 cm2 all-inorganic perovskite solar cell can be achieved at AM 1.5G solar irradiation. To the best of our knowledge, this is one of the highest efficiency reported for carbon electrode based all-inorganic perovskite solar cells so far, and the first report of 1 cm2 carbon counter electrode based inorganic perovskite solar cell with PCE exceeding 13%. Moreover, the inorganic perovskite/carbon quantum dot graded heterojunction photovoltaics maintained over 90% of their initial efficiency after thermal aging at 85° for 1056 hours. This conception of constructing inorganic perovskite/FCQDs graded heterojunction offers a feasible pathway to develop efficient and stable photovoltaics for scale-up and practical applications
Single‐Crystal Nanowire Cesium Tin Triiodide Perovskite Solar Cell
Abstract This work reports for the first time a highly efficient single‐crystal cesium tin triiodide (CsSnI 3 ) perovskite nanowire solar cell. With a perfect lattice structure, low carrier trap density (≈5 × 10 10 cm −3 ), long carrier lifetime (46.7 ns), and excellent carrier mobility (>600 cm 2 V −1 s −1 ), single‐crystal CsSnI 3 perovskite nanowires enable a very attractive feature for flexible perovskite photovoltaics to power active micro‐scale electronic devices. Using CsSnI 3 single‐crystal nanowire in conjunction with highly conductive wide bandgap semiconductors as front‐surface‐field layers, an unprecedented efficiency of 11.7% under AM 1.5G illumination is achieved. This work demonstrates the feasibility of all‐inorganic tin‐based perovskite solar cells via crystallinity and device‐structure improvement for the high‐performance, and thus paves the way for the energy supply to flexible wearable devices in the future
Surface Modification in CsPb<sub>0.5</sub>Sn<sub>0.5</sub>I<sub>2</sub>Br Inorganic Perovskite Solar Cells: Effects of Bifunctional Dipolar Molecules on Photovoltaic Performance
Inorganic tin–lead binary perovskites have piqued
the interest
of researchers as effective absorbers for thermally stable solar cells.
However, the nonradiative recombination originating from the surface
undercoordinated Sn2+ cations and the energetic offsets
between different layers cause an excessive energy loss and deteriorate
the perovskite device’s performance. In this study, we investigated
two thioamide derivatives that differ only in the polar part connected
to their common benzene ring, namely, benzenecarbothioamide and 4-fluorophenylcarbothioamide
(F-TBA). These two molecules were implemented as modifiers onto the
inorganic tin–lead perovskite (CsPb0.5Sn0.5I2Br) surface in the perovskite solar cells. Modifiers
that carry CS and NH2 functional groups, equipped
with lone electron pairs, can autonomously associate with surface
Sn2+ through coordination and electrostatic attraction
mechanisms. This interaction serves effectively to passivate the surface.
In addition, due to the permanent dipole moment of the intermediate
layer, an interfacial dipole field appears at the PCBM/CsPb0.5Sn0.5I2Br interface, reducing the electron
extraction potential barrier. Consequently, the planar solar cell
with an ITO/PEDOT:PSS/CsPb0.5Sn0.5I2Br/PCBM/BCP/Ag layered structure featuring an F-TBA surface post-treatment
demonstrated a noteworthy power conversion efficiency of 14.01%. Simultaneously,
after being stored for 1000 h in an inert atmosphere glovebox, the
non-encapsulated CsPb0.5Sn0.5I2Br
solar cells managed to preserve 94% of their original efficiency