JIALINGBO

Organic molecule dopants of fluorophenylboronic acids (F-PBAs) act as crystal cross-linkers between neighboring perovskite grains through hydrogen bonding and coordination bonding, yielding high-quality perovskite films with reduced grain boundary defects. Benefiting from the effective perovskite crystal cross-linking, a remarkable augmentation of the efficiency from 16.4% to nearly 20% has been achieved, while simultaneously enhancing moisture/thermal/light stability of MAPbI₃-based PSCs.

Abstract

Organic-inorganic metal halide perovskites are regarded as one of the most promising candidates in the photovoltaic field, but simultaneous realization of high efficiency and long-term stability is still challenging. Here, a one-step solution-processing strategy is demonstrated for preparing efficient and stable inverted methylammonium lead iodide (MAPbI₃) perovskite solar cells (PSCs) by incorporating a series of organic molecule dopants of fluorophenylboronic acids (F-PBAs) into perovskite films. Studies have shown that the F-PBA dopant acts as a cross-linker between neighboring perovskite grains through hydrogen bonds and coordination bonds between F-PBA and perovskite structures, yielding high-quality perovskite crystalline films with both improved crystallinity and reduced defect densities. Benefiting from the repaired grain boundaries of MAPbI₃ with the organic cross-linker, the inverted PSCs exhibit a remarkably enhanced performance from 16.4% to approximately 20%. Meanwhile, the F-PBA doped devices exhibit enhanced moisture/thermal/light stability, and specially retain 80% of their initial power conversion efficiencies after more than two weeks under AM 1.5G one-sun illumination. This work highlights the impressive advantages of the perovskite crystal cross-linking strategy using organic molecules with strong intermolecular interactions, providing an efficient route to prepare high-performance and stable planar PSCs.

Nature Communications, Published online: 23 August 2021; doi:10.1038/s41467-021-25407-8

Here comes the sun: A comprehensive Review on the defect passivation of perovskite solar cells (PSCs) from a molecule design viewpoint is reported. First, the influence of defects on the photovoltaic parameters of PSCs is demonstrated. Then, the structure-performance correlation of the passivation molecule is investigated. Finally, a perspective on future trends of passivation strategies is provided.

Abstract

Perovskite solar cells (PSCs) are a promising third-generation photovoltaic (PV) technology developed rapidly in recent years. Further improvement of their power conversion efficiency is focusing on reducing the non-radiative charge recombination induced by the defects in metal halide perovskites. So far, defect passivation by the organic small molecule has been considered as a promising approach for boosting the PSC performance owing to their large structure flexibility adapting to passivating variable kinds of defect states and perovskite compositions. Here, the recent progress of defect passivation toward efficient and stable PSCs was reviewed from the viewpoint of molecular structure design and device performance. To comprehensively reveal the structure-performance correlation of passivation molecules, it was separately discussed how the functional groups, organic frameworks, and side chains affect the corresponding PV parameters of PSCs. Finally, a guideline was provided for researchers to select more suitable passivation agents, and a perspective was given on future trends in development of passivation strategies.

Interfacial nonradiative recombination limits the open-circuit voltage of perovskite solar cells. A buried interface passivation strategy is developed that can be used across metal oxide transport layers. Perovskite precursors containing large organic cations with high affinity for the substrate spontaneously form a 2D passivation layer on the underlying metal oxides, which reduces interfacial recombination by 72%.

Abstract

The open-circuit voltage (V _oc) of perovskite solar cells is limited by non-radiative recombination at perovskite/carrier transport layer (CTL) interfaces. 2D perovskite post-treatments offer a means to passivate the top interface; whereas, accessing and passivating the buried interface underneath the perovskite film requires new material synthesis strategies. It is posited that perovskite ink containing species that bind strongly to substrates can spontaneously form a passivating layer with the bottom CTL. The concept using organic spacer cations with rich NH₂ groups is implemented, where readily available hydrogens have large binding affinity to under-coordinated oxygens on the metal oxide substrate surface, inducing preferential crystallization of a thin 2D layer at the buried interface. The passivation effect of this 2D layer is examined using steady-state and time-resolved photoluminescence spectroscopy: the 2D interlayer suppresses non-radiative recombination at the buried perovskite/CTL interface, leading to a 72% reduction in surface recombination velocity. This strategy enables a 65 mV increase in V _oc for NiO _x based p–i–n devices, and a 100 mV increase in V _oc for SnO₂-based n–i–p devices. Inverted solar cells with 20.1% power conversion efficiency (PCE) for 1.70 eV and 22.9% PCE for 1.55 eV bandgap perovskites are demonstrated.

An environmentally benign material, histamine (HA), is used to intentionally passivate the V_I in the CsPbI_3−x Br _x perovskite thin films. The synergistic effect of Lewis base–acid interaction and H-bond strengthens the adsorption of HA molecules on the surface of perovskite. The fabricated PSCs with HA passivation significantly reduced the number of uncoordinated Pb²⁺ and achieved a record 20.8 % efficiency.

Abstract

Iodine vacancies (V_I) and undercoordinated Pb²⁺ on the surface of all-inorganic perovskite films are mainly responsible for nonradiative charge recombination. An environmentally benign material, histamine (HA), is used to passivate the V_I in perovskite films. A theoretical study shows that HA bonds to the V_I on the surface of the perovskite film via a Lewis base–acid interaction; an additional hydrogen bond (H-bond) strengthens such interaction owing to the favorable molecular configuration of HA. Undercoordinated Pb²⁺ and Pb clusters are passivated, leading to significantly reduced surface trap density and prolonged charge lifetime within the perovskite films. HA passivation also induces an upward shift of the energy band edge of the perovskite layer, facilitating interfacial hole transfer. The combination of the above raises the solar cell efficiency from 19.5 to 20.8 % under 100 mW cm⁻² illumination, the highest efficiency so far for inorganic metal halide perovskite solar cells (PSCs).

Publication date: November 2021

Source: Nano Energy, Volume 89, Part B

Author(s): Xin Wang, Yuankun Qiu, Luyao Wang, Tiankai Zhang, Lei Zhu, Tong Shan, Yong Wang, Jinkun Jiang, Lingti Kong, Hongliang Zhong, Haomiao Yu, Feng Liu, Feng Gao, Feng Wang, Chun-Chao Chen

A 2D perovskite passivation scheme based on octylammonium chloride provides combined bulk and surface passivation of 3D perovskite film through Cl⁻ diffusion into the 3D perovskite bulk.

Abstract

Dimensional engineering of perovskite films is a promising pathway to improve the efficiency and stability of perovskite solar cells (PSCs). In this context, surface or bulk passivation of defects in 3D perovskite film by careful introduction of 2D perovskite plays a key role. Here the authors demonstrate a 2D perovskite passivation scheme based on octylammonium chloride, and show that it provides both bulk and surface passivation of 1.6 eV bandgap 3D perovskite film for highly efficient (≈23.62%) PSCs with open-circuit voltages up to 1.24 V. Surface and depth-resolved microscopy and spectroscopy analysis reveal that the Cl⁻ anion diffuses into the perovskite bulk, passivating defects, while the octylammonium ligands provide effective, localized surface passivation. The authors find that the Cl⁻ diffusion into the perovskite lattice is independent of the 2D perovskite crystallization process and occurs rapidly during deposition of the 2D precursor solution. The annealing-induced evaporation of Cl from bulk perovskite is also inhibited in 2D–3D perovskite film as compared to pristine 3D perovskite, ensuring effective bulk passivation in the relevant film.

1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi) is introduced via an antisolvent engineering to regulate the growth of perovskite film. Upon the incorporation of TPBi, the perovskite film obtains a higher crystallinity and enhanced hole blocking capability on the surface. The TPBi-incorporated perovskite solar cell delivers a high efficiency of 21.79% and keeps ≈92% of the initial value after 1000 h in the ambient atmosphere.

Abstract

With potential commercial applications, inverted perovskite solar cells (PSCs) have received wide-spread attentions as they are compatible with tandem devices and processed at low-temperature. Nevertheless, their efficiencies remain unsatisfactory due to insufficient film quality on hydrophobic hole transport layer and limited hole-blocking capability of the electron transport layer. Herein, 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi), an n-type semiconductor, is incorporated into the antisolvent to simultaneously regulate the grain growth and charge transport of perovskite films. TPBi facilitates the crystallization of perovskites along (100) orientation. Besides, TPBi is mainly distributed near the top surface of perovskite film and enhances the hole-blocking capability of the area adjacent to the surface. The superior properties of this film lead to a remarkable improvement in the open-circuit voltage of inverted PSCs. The champion device achieves a high power conversion efficiency of 21.79% while keeping ≈92% of its initial value after 1000 h storage in the ambient atmosphere. This work provides an effective way to evidently promote the performance of inverted PSCs and illustrates its underlaying mechanism.

The intrinsic mechanisms of doping effects on improving or decreasing the efficiency of organic–inorganic hybrid perovskite (OIHP) solar cells are qualitatively and quantitatively clarified. The influences of the doping concentration, defects, trap density, and carrier mobility on the parameters (J _SC, V _OC, fill factor, and power conversion efficiency) of OIHP solar cells are identified by means of spectroscopic investigations.

Abstract

To enhance the efficiency and stability of the organic–inorganic hybrid perovskite (OIHP) solar cells, doping has been demonstrated as a straightforward method. Nevertheless, the perception of trap states regulated by doping and their effects on the performance of solar cells is not in-depth. Herein, typical OIHPs (CH₃NH₃PbI₃ and Cs_0.05FA_0.85MA_0.10Pb(I_0.97Br_0.03)₃) doped with RbI are employed to expound the doping mechanism in affecting the efficiency of devices. Systematic spectroscopic characterizations indicate that doping significantly influences the photocarrier dynamics via directly regulating the trap states. The results indicate that doping would reduce the trap density by passivating defects and induce extra trapping centers. This directly manipulates the transient transport of the photocarriers and finally influences the output of devices. The optimization of solar cell performance requires the tradeoff of competitive relation between the passivation and introduction of trapping centers. The results provide the spectroscopic perception on how doping concentration affects trap density, carrier dynamics, transport behavior, and ultimately the parameters of devices. It provides a straightforward guidance to the design and optimization of OIHP-based solar cells.

Adding MACl in perovskite (PVK) precursor promotes the PVK crystals vertical growth and reduces the vertical grain boundaries. The MACl-added PVK films show widened bandgap and accelerate the carriers vertical transport and extraction. Using the MACl additive engineering, a champion rear-textured PVK/silicon heterojunction tandem solar cell is obtained with a V _OC of 1.93 V and a PCE of 24.16%.

The efficiency of perovskite (PVK)/silicon tandem solar cells have the potential to beyond the Shockley–Queisser limit of single-junction solar cell and the theoretical efficiency can reach over 35%. Improving the quality of PVK film can reduce nonradiative charge recombination. Herein, MACl is added to the PVK precursor, compared with the control cell, adding MACl can assist the vertical crystallization of PVK film, accelerates carrier vertical transport, reduces bulk defects in the active layer. Moreover, MACl can upshift the valence band energy level, making it better band alignment with hole-transport layer. As a result, the fill factor (FF) and open-circuit voltage (V _OC) are improved with MACl addition. The champion MACl-added PVK solar cell with 1.67 eV bandgap achieves an efficiency of 18.94% and a V _OC of 1.225 V. Using the optimized wide bandgap PVK solar cells to fabricate the rear-textured monolithic PVK /silicon heterojunction tandem solar cells, a champion efficiency of 24.16% and a V _OC of 1.93 V are obtained. It is demonstrated that the control of PVK crystals vertical orientation provides an effective strategy for improving the efficiency of PVK-based solar cells.

Publication date: November 2021

Source: Nano Energy, Volume 89, Part A

Author(s): Kyungeun Jung, Kwonwoo Oh, Du Hyeon Kim, Jae Won Choi, Ki Chul Kim, Man-Jong Lee

Publication date: November 2021

Source: Nano Energy, Volume 89, Part A

Author(s): Yongrui Yang, Fanyi Min, Yali Qiao, Zheng Li, Florian Vogelbacher, Zhaoxin Liu, Wenkun Lv, Yang Wang, Yanlin Song

Two regular terpolymers are used as the effective dopant-free hole transport materials for inverted perovskite solar cells. The power conversion efficiency of solar cells can reach up to 18.17%, with negligible hysteresis and good ambient stability, which is mainly due to the well-matched energy level, improved film morphology, low carrier recombination, and higher hole extraction efficiency of the perovskite layer.

In inverted perovskite solar cells (PSCs), hole transport materials (HTMs) can efficiently improve hole extraction and transfer as well as the crystallization of perovskite films and thus enhance the photovoltaic performance. Herein, two dopant-free, regular A₁–D–A₂–D-type (D: electron donor; A: electron acceptor) polymeric HTMs, PTPDTBT and PDPPTBT, are developed by integrating the benzothiadiazole unit (A₁) with the electron-accepting species of either a thieno[3,4-c]pyrrole-4,6-dione or a pyrrolo[3,4-c]pyrrole-1,4-dione segment (A₂), respectively, where the thiophene unit (D) results in a kinked molecular geometry. These A₁–D–A₂–D-type terpolymers exhibit comparable nonpolar properties but distinct film-quality morphology and charge transport characteristics. PDPPTBT with the more insulating side-chain groups is found to improve the quality of perovskite films cast on top with larger grain sizes and more homogeneous crystallization. As a consequence, the PDPPTBT-based PSCs without any dopants and additional interlayers display a champion power conversion efficiency of 18.17%, one of the highest values of MAPbI₃-based inverted PSCs using dopant-free D-A-type polymeric HTMs. Furthermore, the PDPPTBT-based device exhibits negligible hysteresis and high long-term stability. This work provides a potential strategy to design dopant-free A₁–D–A₂–D-type polymeric HTMs for efficient and stable PSCs.

Dopant engineering for spiro-OMeTAD hole-transporting materials towards efficient perovskite solar cells. The presence of M(TFSI) _n salts as p-type dopants are required to improve the hole transfer of spiro-OMeTAD, critical for photovoltaic performance. This study assesses the role of metal cations in the process, revealing the superiority of Zn-based dopants as compared to redox-active Cu-based ones and others as producing a very high fill factor of close to 80% a V _OC of 1.15 V and a power conversion efficiency of 21.9%.

Abstract

One of the most prominent hole-transporting material (HTM) for hybrid perovskite solar cells has been 2,2″,7,7″-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene (spiro-OMeTAD), which is commonly doped with metal bis(trifluoromethylsulfonyl)imide (M(TFSI) _n ) salts that contribute to generating the active radical cation HTM species. The underlying role of the metal cation, however, remains elusive. Here, the effect of metal cations (M = Li, Zn, Ca, Cu, and Sc) on doping spiro-OMeTAD is analyzed by a combination of techniques, including electron paramagnetic resonance spectroscopy and cyclic voltammetry, which is complemented by photovoltaic device and hole mobility analysis. As a result, the authors reveal the superiority of Zn(TFSI)₂ salts in device performances as compared to the others, including redox-active Cu(TFSI)₂. This analysis thereby unravels new design principles for dopant engineering in HTMs for hybrid perovskite photovoltaics.

A novel hole-transport material (HTM) with the ability to bind to perovskites via halogen bonding is synthesized. Thanks to this interaction, the HTM molecules form a homogenous and ordered layer, improving the perovskite/HTM interface. This results in enhanced open circuit voltage and stability, showing the advantages of using halo-functional HTMs in perovskite solar cells.

Abstract

Interfaces play a crucial role in determining perovskite solar cells, (PSCs) performance and stability. It is therefore of great importance to constantly work toward improving their design. This study shows the advantages of using a hole-transport material (HTM) that can anchor to the perovskite surface through halogen bonding (XB). A halo-functional HTM (PFI) is compared to a reference HTM (PF), identical in optoelectronic properties and chemical structure but lacking the ability to form XB. The interaction between PFI and perovskite is supported by simulations and experiments. XB allows the HTM to create an ordered and homogenous layer on the perovskite surface, thus improving the perovskite/HTM interface and its energy level alignment. Thanks to the compact and ordered interface, PFI displays increased resistance to solvent exposure compared to its not-interacting counterpart. Moreover, PFI devices show suppressed nonradiative recombination and reduced hysteresis, with a V _oc enhancement of ≥20 mV and a remarkable stability, retaining more than 90% efficiency after 550 h of continuous maximum-power-point tracking. This work highlights the potential that XB can bring to the context of PSCs, paving the way for a new halo-functional design strategy for charge-transport layers, which tackles the challenges of charge transport and interface improvement simultaneously.

Eu-MOF is introduced to the field of perovskite solar cells. Both Eu ions and organic ligands reduce the defect concentration. More over, due to the Förster resonance energy transfer effect, Eu-MOF improves the light utilization. Meanwhile, it also turns tensile strain to compressive strain. Finally, the device performance, in efficiency and stability, is increased dramatically due to the synergetic effects.

Abstract

Enhancing device lifetime is one of the essential challenges in perovskite solar cells. The ultrathin Eu-MOF layer is introduced at the interface between the electron-transport layer and the perovskite absorber to improve the device stability. Both Eu ions and organic ligands in the MOF can reduce the defect concentration and improve carrier transport. Moreover, due to the Förster resonance energy transfer effect, Eu-MOF in perovskite films can improve light utilization and reduce the decomposition under ultraviolet light. Meanwhile, Eu-MOF also turns tensile strain to compressive strain in the perovskite films. As a result, the corresponding devices achieve a champion power conversion efficiency (PCE) of 22.16%. In addition, the devices retain 96% of their original PCE after 2000 h under the relative humidity of 30% and 91% of their original PCE after 1200 h after continuous 85 °C aging condition in N₂.

Based on organotrichlorosilane post-treatment, high-performance color-stable deep-blue perovskite light-emitting diodes that satisfy the latest Rec. 2020 standard are successfully demonstrated. The best deep-blue device shows a maximum external quantum efficiency of 1.1% with an emission peak of 458 nm, representing a state-of-the-art result for thin-film perovskite light-emitting diodes in this emission region.

Abstract

Recent studies of sky-blue perovskite light-emitting diodes (PeLEDs) have extensively promoted optimal device design to achieve an external quantum efficiency (EQE) above 12%. However, the development of thin-film deep-blue PeLEDs lags dramatically behind, especially with regards to meeting the latest Rec. 2020 standard. A trichloro(3,3,3-trifluoropropyl) silane post-treatment that drives the emission of perovskite into the deep-blue region, ranging from 440 to 460 nm, which meets the Rec. 2020 standard, is proposed. The chlorine ions released from the organotrichlorosilane molecules during their polycondensation reaction provide an addition halide source to fine tune the composition of the mixed halide perovskite films, leading to increase of bandgap and deep-blue emission. In addition, hydrogen bonds between the hydroxy groups of silane molecules and halide anions in perovskite can suppress ion migration for improving emission stability. As a result, an optimal PeLED is developed with deep-blue emission at 458 nm and excellent color stability, which yields an EQE and luminance of 1.1% and 130 cd m⁻², respectively, representing a state-of-the-art result for thin-film PeLEDs in this emission region. This work paves the way to achieve high-performance deep-blue PeLEDs with stable emissions to meet the demand for potential applications such as full-color display.

Perovskite Solar Cells

In article number 2100257, Ming-Chung Wu, Kun-Mu Lee, and co-workers demonstrate an approach where two-dimensional g-C₃N₄ is applied as a template for controlling the nucleation of the perovskite active layer. Adding the urea-polymerized g-C₃N₄ into the perovskite active layer allows for a uniform surface morphology and a reduced trap density. Over 20% power conversion efficiency of perovskite solar cells with superior stability was achieved by the unencapsulated perovskite solar cells with g-C₃N₄.

Perovskite solar cells are poised to take the next step into commercialization. Hole-transporting materials are central components of these devices, which determine the actual efficiency and durability by controlling interfacial charge extraction/transport processes and exchanges with the external environment. Herein, the evolution in the engineering of these layers is analyzed, revealing their “non-innocent role” in driving device performance.

The race to the future generation of low-cost photovoltaic devices continuously takes on added momentum with the appearance of novel practical solutions for the fabrication of perovskite solar cells (PSCs), a paradigm technology for ultracheap light-to-electricity conversion. Much has been done in the past few years toward defining standard protocols for the assessment of their efficiency and stability, aiming at achieving a worldwide consensus on the issue, that will allow reliable reporting of new data. While this is undoubtedly a step ahead toward commercialization of these devices, it also often triggers researchers to test record architectures using benchmark configurations, mainly for what regards the ancillary layers that extract electrical charges from the photoexcited perovskite. In particular, the mostly used hole-transporting material (HTM) is the small-molecule spiro-OMeTAD, which is also well known to be the origin of PSC degradation after prolonged operation. Herein, it is aimed to remark the huge impact of the HTM on PSC performance, recalling major issues associated with the conventional spiro-based one and providing an overview of state-of-the-art alternatives. Finally, possible scenarios for the future development of smart HTMs are also envisioned, as charge-extracting layers, with a real active role in ensuring PSC operational stability.

Perovskite/silicon tandem solar cells are a cost-effective technology with a promising future as mainstream photovoltaic technology. Currently, many efforts are placed to further improve the performances of the tandem module. However, little is known about the module requirements for this technology. Here, the main challenges towards tandem module manufacturing are discussed, in view of a swift commercialization of this technology.

Over the past few years, perovskite solar cells have arisen as a technology to potentially side with mainstream silicon photovoltaics (PVs) to help drive the transition towards renewable sources of energy. The coupling of perovskites with silicon in a tandem configuration may accelerate this development due to the remarkably high power conversion efficiencies possible with such devices. However, most of the perovskite/silicon tandem achievements so far have been confined to the lab environment, with only a few reported tests under outdoor conditions, using packaged devices. Nevertheless, one of the major challenges for perovskite/silicon tandem technologies, in addition to scale-up, lies in the cell-to-module (CTM) translation, which for the perovskite/silicon tandem concept is complicated by perovskite-imposed constrains such as a low-temperature resilience, imposing challenges regarding tabbing and lamination, as well as a high sensitivity to moisture ingress, mandating the search for adequate encapsulation materials and methods. Herein, these challenges are described and assessed in depth and a perspective on future directions toward module design, tailored for perovskite/silicon tandem PVs is given, combining high performance with excellent durability. The discussion also holds relevance for all-perovskite and other emerging PV technologies seeking market entry.

A rationally designed reductive molecule, 4-fluorophenylhydrazine hydrochloride (4F-PHCl), with multiple active sites for passivating defects, enhancing antioxidation, improving hydrophobicity, and minimizing nonradiative recombination in efficient and stable perovskite solar cells.

The defects (e.g., I₂, anion, and cation vacancies) in the perovskite films are detrimental to the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs). Herein, a multifunctional additive molecule 4-fluorophenylhydrazine hydrochloride (denoted as 4F-PHCl) is reported, which can improve perovskite crystallization, passivate film defects, and enhance film moisture stability, finally leading to the simultaneous increase in PCE and stability. It is revealed that the hydrazine functional group can effectively reduce the I₂ defects back to I^-. In addition, the hydrazinium contained cations and chloride anions can passivate the cationic defects (like anion vacancies) and anionic defects (like cation vacancies), respectively. The hydrophobic fluorinated benzene ring should be mainly responsible for the enhanced moisture stability of films and devices. As a result, the 4F-PHCl-modified device achieves a promising efficiency of 21.80% along with a high open-circuit voltage of 1172 mV and exhibits excellent long-term ambient stability. A guide for developing multifunctional additive molecules for the simultaneous enhancement of efficiency and stability is provided.

The small bifunctional molecule 1,2-benzisothiazolin-3-one (BIT) is used as an additive and coverage layer, respectively, to enhance the performance and stability of the perovskite device. Both theoretical calculation and characterization of specimens indicate that the trap defect states are suppressed. The result of passivation strategy demonstrates a substantial enhancement in solar cell performance and stability.

Even though the perovskite material itself has a high defect tolerance compared with other semiconductors, the defects existing at grain boundaries (GBs) or the surface still cause high densities of the trap state which impair the efficiency and stability of perovskite solar cells (PSCs). Herein, the small molecule 1,2-benzisothiazolin-3-one (BIT) is investigated to passivate the defects at the GBs and surface of perovskite films. The results reveal that the BIT molecule belongs to a type of bifunctional species, which functions as cations and anions to passivate the perovskite surface. The BIT passivation generates lower formation energy and a more stable perovskite structure, resulting in improved performance and stability of the PSCs. The power conversion efficiency (PCE) of the optimized inverted photovoltaic device reaches 21.83%. Meanwhile, high photostability is achieved for PSCs with an efficiency drop of less than 10% under continuous light illumination over 500 h.