An in situ bifacial passivation strategy for flexible perovskite solar module with mechanical robustness by roll-to-roll fabrication

Abstract

The inevitably interfacial defects in the under layer of perovskite films still trouble the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs), especially for large-area flexible devices...

Printable and Homogeneous NiOx Hole Transport Layers Prepared by a Polymer‐Network Gel Method for Large‐Area and Flexible Perovskite Solar Cells

“…The valence band maximum (VBM) values can be calculated according to the formula of VBM = W F + (E F − E VB ), where W F is work function, E F is Fermi level, and E VB is valence band energy level. [15] The VBM energy (5.36 eV) of the optimized NiO x films is more aligned with the valence band (5.47 eV) of the perovskite, which predicts an optimization of open-circuit voltage (V oc ) for PSCs, resulting that photo-excited holes from perovskite films will be effectively extracted and transferred to the anode. Kelvin probe force microscopy is further used to investigate the surface potential of the NiO x films.…”

“…Subsequently, the above well-dispersed NiO x precursor solutions are applied to fabricate the NiO x films by meniscus-blade coating (Figure 2a). Due to the shear force of the solution, [15,39,40] NiO x NPs are induced to deposit on the indium tin oxide (ITO) substrate. The optimized NiO x film will perform flatter and smoother, compared to the unoptimized NiO x film, which may be due to the reduction of NPs aggregation in the precursor.…”

“…), which is of great significance for the commercialization of perovskite devices. [14,15] However, there exist still some obstacles in pursuing high-performance NiO x -based PSCs, such as the agglomeration of NiO x NPs in the synthesis and dispersion, low intrinsic conductivity, and poor interface contact with perovskite films. [16][17][18][19] Under-coordinated metal cation sites (Ni ≥3+ ) in NiO x act as a brønsted base and experience a deprotonation…”

Materials and Methods for High‐Efficiency Perovskite Solar Modules

“…Wang et al fabricated flexible PSMs based on the roll‐to‐roll process with HI‐assisted passivation on NiO x HTL in a p–i–n‐inverted structure (Figure 7c). [ 100 ] As HI was applied to the NiO x /perovskite interface, the photovoltaic performance of the device was significantly increased due to passivation of interfacial defects by NiI 2 induced by the HI–NiO x reaction and deep defects of perovskites. Thus, high‐quality perovskite films with enlarged grain size were produced.…”

An Embedding 2D/3D Heterostructure Enables High‐Performance FA‐Alloyed Flexible Perovskite Solar Cells with Efficiency over 20%

“…Recent works have demonstrated molecular passivation strategies to heal the defects at surface and grain boundaries of perovskites, leading to improved efficiency and stability of f ‐PSCs. [ 18 , 19 , 20 , 21 , 22 ] Nevertheless, the majority of these high efficiency f ‐PSCs were deposited using spin coating in combination with an antisolvent crystallization process, which is unfortunately neither scalable nor can be transferred to large‐area coating lines. In this circumstance, developing effective strategies allowing for morphology control and defect passivation of flexible perovskite films by scalable deposition process is highly demanded for their large‐scale manufacture.…”