Enhanced Power Conversion Efficiency Research Articles

Grain Boundary Defect Passivation of Triple Cation Mixed Halide Perovskite with Hydrazine-Based Aromatic Iodide for Efficiency Improvement

Perovskites have been unprecedented with relatively sharp rise in power conversion efficiency in the last decade. However, the polycrystalline nature of the perovskite film makes it susceptible to surface and grain boundary defects, which significantly impedes its potential performance. Passivation of these defects has been an effective approach to further improve photovoltaic performance of the perovskite solar cells. Here, we report use of a novel hydrazine-based aromatic iodide salt or phenyl hydrazinium iodide (PHI) for secondary post treatment to passivate surface and grain boundary defects in triple cation mixed halide perovskite films. In particular, the PHI post-treatment reduced current at the grain boundaries, facilitated an electron barrier and reduced trap state density, indicating suppression of leakage pathways and charge recombination, thus passivating the grain boundaries. As a result, a significant enhancement in power conversion efficiency to 20.6% was obtained for the PHI-treated perovskite device in comparison to control device with 17.4%.

Orthogonal Printable Reduced Graphene Oxide 2D Materials as Hole Transport Layers for High-Performance Inverted Polymer Solar Cells: Sheet Size Effect on Photovoltaic Properties.

Creating an orthogonal printable hole-transporting layer (HTL) without damaging the underlying layer is still a major challenge in fabricating large-area printed inverted polymer solar cells (PSCs). In this study, we prepared orthogonal-processable fluorine-functionalized reduced graphene oxide (FrGO) series with various two-dimensional sheet sizes such as large-sized FrGO (1.1 μm), medium-sized FrGO (0.7 μm), and small-sized FrGO (0.3 μm) and systematically investigated the size effect of FrGOs on the hole transport properties of PSCs. The FrGOs exhibit highly stable dispersion without change over 90 days in 2-propanol solvent, indicating very high dispersion stability. Decreasing the sheet size of FrGOs enhanced hole-transporting properties, resulting in power conversion efficiencies (PCEs) of 9.27 and 9.02% for PTB7-Th:EH-IDTBR- and PTB7-Th:PC71BM-based PSCs, respectively. Compared to devices with solution-processed poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), a 14% enhancement of PCEs was achieved. Interestingly, the PCEs of devices with the smallest FrGO sheet are higher than the PCE of 8.77% of a device with vacuum-deposited MoO3. The enhancement in the performance of PSCs is attributed to the enhanced charge collection efficiency, decreased leakage current, internal resistance, and minimized charge recombination. Finally, small-sized FrGO HTLs were successfully coated on the photoactive layer using the spray coating method, and they also exhibited PCEs of 9.22 and 13.26% for PTB7-Th:EH-IDTBR- and PM6:Y6-based inverted PSCs, respectively.

Enabling High-Performance Tandem Organic Photovoltaic Cells by Balancing the Front and Rear Subcells.

In tandem organic photovoltaics, the front subcell is based on large-bandgap materials, whereas the case of the rear subcell is more complicated. The rear subcell is generally composed of a narrow-bandgap acceptor for infrared absorption but a large-bandgap donor to realize a high open-circuit voltage. Unfortunately, most of the ultraviolet-visible part of the photons are absorbed by the front subcell; as a result, in the rear subcell, the number of excitons generated on large-bandgap donors will be reduced significantly. This reduces the (photo) conductivity and finally limits the hole-transporting property of the rear subcell. In this work, a simple and effective way is proposed to resolve this critical issue. To ensure sufficient photogenerated holes in the rear subcell, a small amount of an infrared-absorbing polymer donor as a third component is introduced, which provides a second hole-generation and transporting mechanism to minimize the aforementioned detrimental effects. Finally, the short-circuit current density of the two-terminal tandem organic photovoltaic is significantly enhanced from 10.3 to 11.7mAcm-2 (while retaining the open-circuit voltage and fill factor) to result in an enhanced power conversion efficiency of 15.1%.

Water/Ethanol Soluble p-Type Conjugated Polymers for the Use in Organic Photovoltaics

We have developed two series of p-type conjugated polymers based on poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl] (TQ1) polymeric backbone utilizing polar pendant groups, i.e., tertiary amine and pyridine, to achieve switchable solubility in water and ethanol. By balancing the ratio between polar and non-polar side-groups, we could combine green-solvent processability with the manufacturing of functional photovoltaic devices. Due to the unavailability of water/alcohol soluble acceptors, the photovoltaic performance of these new polymers was evaluated using organic solvent by incorporating PC61BM. For water/alcohol soluble partial amine-based polymers, we achieve a maximum power conversion efficiency (PCE) of ∼0.8% whereas alcohol soluble partial pyridine-based polymers show enhanced PCE of ∼1.3% with inverted device structure. We propose that the enhancement in PCE is a result of the reduction in amino-group content and the lower basicity of pyridine, both of which decrease the interaction between functionalized polymers with the anode interface material and reduce the miscibility of the donor and acceptor. Further improvement of the photovoltaic performance, in particular the open-circuit voltage (Voc), was achieved by using an anode buffer layer to mitigate the unfavorable interaction of the amino/pyridine groups with the MoO3 electrode. Our work demonstrated the possibility of substituent modification for conjugated polymers using tertiary amine and pyridine groups to achieve water/alcohol soluble and functional donor materials.

Microstructured CH3NH3PbI3 films for Efficient Solar Cells under Ambient Conditions

We demonstrate antisolvent vapor assisted diffusion as a unique technique for controlled nucleation and better crystallization of methylammonium lead iodide, perovskite absorber film for solar cell applications. Our observations also suggest that due to non-covalent weak interaction between the perovskite absorber and the high boiling point antisolvent, Ethylacetate (EA), a new microstructured morphology (micro-rods) evolves in the film, which we report for the first time. It is believed that the changed morphology of the mesoporous films for the high boiling point antisolvent, exhibits better fill factor and results in 32% enhancement of power conversion efficiency than the low boiling point antisolvent, Dichloromethane (DCM), diffused and as-deposited films, thereby suggesting one more parameter to achieve better device performance.

Performance of Air-Stable Cs<sub>2</sub>SnI<sub>6</sub> Perovskite as Electron Transport Layer in Inverted Bulk Heterojunction Solar Cell

In recent years, perovskite material has been extensively studied due to its unique physical properties and promising application in the third generation of solar cells. In particular, Sn-based perovskite has been considered to replace Pb-based perovskite because of the toxic effects and it can lead to other serious problems related to the environment. Cs2SnI6 perovskite has been known to be synthesized in a simple chemical process and it can be produced on a large scale. Moreover, this material is also oxygen and moisture stable due to the high oxidation state of tin. In this study, we synthesize air-stable Cs2SnI6 perovskite by the use of the wet chemical process at room temperature. Next, we attempt to fabricate the inverted bulk heterojunction solar cells incorporated Cs2SnI6 as electron transport layer in the configuration of ITO/ZnO/Cs2SnI6/P3HT:PCBM/PEDOT:PSS/Ag to improve device performance. The Cs2SnI6 perovskite shows an Fm-3m space group with a cubic lattice parameter of 11.62Å confirmed by X-Ray Diffraction (XRD) measurement, while UV-Vis measurement indicates this type of perovskite has direct band gap ~3.1 eV. The fabricated solar cell device reveals the enhancement in current density at short circuit condition (Jsc) from 64.69 mA/cm2 to 77.02 mA/cm2 with the addition of 2.25 mg/ml Cs2SnI6 along with the enhancement of power conversion efficiency (PCE) from 7.05% to 9.75% as characterized by J-V measurement. In our case, the voltage at open circuit condition (Voc) of the device does not perform significant improvement. Besides, it is found that the solar cell devices are quite stable even after exposure in the air for six weeks after fabrication, as indicated by PCE performance.

Photovoltaic Characterization of Hybrid Bulk Heterojunction Solar Cell Incorporated Gold Nanoparticles Embedded in Active Layer

We attempt to study the effect of gold nanoparticles embedded into the active polymer of regioreguler poly (3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) on the charge kinetic to enhance the performance of bulk-heterojunction solar cell. It has been known that the generation of localized surface plasmon resonance (LSPR) would both increase the photon absorption and improve the efficiency of charge separation. Synthesis of gold nanoparticles stabilized by oleylamine (AuOA) was carried out by reduction method and resulted in the spherical shape of nanoparticles with a diameter size of ~12 nm. The absorbance spectra show the typical of surface plasmon peak of AuOA in solution at ~527 nm. Fabrication of inverted bulk-heterojunction solar cell device was done in the configuration of ITO/ZnO/P3HT:PCBM:AuOA/PEDOT:PSS/Ag. Incorporation of AuOA in polymer solution is clearly detected from the enhanced absorbance peak resulted from UV-Vis measurement and the mix solution of P3HT:PCBM:AuOA is quite stable in the concentration of AuOA less than 10 wt%. In our experiment, fabricated solar cell reveals the enhancement in current density at short circuit condition (Jsc) from 44.57 mA/cm2 to 56.14 mA/cm2 with the addition of 3.9 wt% AuOA in polymer solution along with the enhancement of power conversion efficiency (PCE) from 4.07% to 6.23% as characterized by J-V measurement. In our case, the voltage at open circuit condition (Voc) of the device does not show significant improvement.

Enhancement in power conversion efficiency of CdS quantum dot sensitized solar cells through a decrease in light reflection

In this research, the effect of a Magnesium Fluoride (MgF2) Anti-Reflection (AR) layer was investigated in quantum dot sensitized solar cells (QDSCs). MgF2 nanoparticles with the dominant size of 20 nm were grown by a thermal evaporation method and a thin layer was formed on the front side of the fluorine-doped tin oxide (FTO) substrate. In order to study the effect of the AR layer on the efficiency of solar cells, this substrate was utilized in CdS QDSCs. In this conventional structure of QDSC, TiO2 nanocrystals (NCs) were applied on the FTO substrate, and then it was sensitized with CdS quantum dots (QDs). According to the results, the QDSCs with a MgF2 AR layer represented the maximum Power Conversion Efficiency (PCE) of 3%. This efficiency was increased by about 47% compared to the reference cell without the AR layer. The reason is attributed to the presence of the AR layer and the reduction of incident light reflected from the surface of the solar cell.

Toward high-efficiency and thermally-stable perovskite solar cells: A novel metal-organic framework with active pyridyl sites replacing 4-tert-butylpyridine

4-tert-butylpyridine (t-BP), the only liquid phase constituent in hole transport layers (HTLs) of perovskite solar cells (PSCs), volatilizes easily to induce the aggregation, hydration, and ion penetration of lithium salts, thereby seriously impairing the thermal stability of devices. Herein, an efficient strategy is presented to address this issue by developing a novel thermally-stable metal-organic framework (MOF) In-Pyia with active pyridyl sites to replace the volatile t-BP. The In-Pyia-modified PSCs realize enhanced power conversion efficiency (PCE) with low performance fluctuation (19.47 ± 0.79%), significantly outperforming the typical devices employing t-BP (17.42 ± 1.02%). More importantly, In-Pyia fulfills a long-term effectiveness to restrain the negative morphological changes of HTL films, attributed to its robust framework and strong coordination effect between pyridine nitrogen atoms and Li+ ions. Even after the overnight thermal treatment at 85 °C and subsequent exposure to the ambient environment (25 °C and relative humidity of ~40%) for 16 days without any encapsulation, the In-Pyia-modified PSCs still maintain 80.9% of the initial PCE, while below 20% is left to the t-BP-controlled devices. This is the first example involving a MOF material as the substitute of t-BP, providing a new feasible strategy to fabricate high-efficiency and thermally-stable PSCs.

Optimization of titanium dioxide decorated by graphene quantum dot as a light scatterer for enhanced dye-sensitized solar cell performance

Titanium dioxide (TiO 2 ) as a photoanode in dye-sensitized solar cells (DSSCs) has some drawbacks that reduce its photovoltaic performances i.e. low dye loading capacity and low light-harvesting efficiency. Therefore, TiO 2 decorated by graphene quantum dot (GQD) as a light scatterer has been successfully fabricated via electrodeposition and drop-casting. The response surface methodology/central composite design was successfully utilized to optimize the preparation of photoanode with TiO 2 -GQD as a light scattering layer (LSL). A reduced quadratic model was successfully designed to predict the power conversion efficiency (PCE) accurately up to 97% with a 3% residual standard error. The TiO 2 -GQD LSL depicted a cluster of spherical nanoparticles on top of the photoanode that not only enhanced the light scattering effect but also improved the light-harvesting range from visible light to ultraviolet and near-infrared range. The resultant TiO 2 nanoparticles with TiO 2 -GQD LSL showed vast enhancement of PCE up to 66% from 3.06% to 5.01% due to a good synergistic effect. • TiO 2 -GQD as light scattering layer (LSL) was optimized using response surface methodology • The reduced quadratic model displays a low residual standard error. • TiO 2 nanoparticles with TiO 2 -GQD LSL displays enhanced efficiency up to 66%.

Highly effective SnS composite counter electrode sandwiched bi-function CeO2:Er3+/Yb3+ assisted surface modified photoelectroded dye sensitized solar cell exceeds 9.5% efficiency

Benefits of cost effective, light weight, coloring, easier processing, DSSCs (dye-sensitized solar cells) are potential substitutes aimed at conversion of solar energy, balancing to the well-established silicon solar photovoltaics. In the present study, CeO2:Er3+/Yb3+ sub-micrometer size upconversion particles prepared through conventional hydrothermal process. Upconversion emission peaks at ~ 652–700 nm along with ~ 520–550 nm are witnessed by excite 980 nm laser light. The light scattering performance is achieved by use of CeO2:Er3+/Yb3+ layer over TiO2 film. Insertion of CeO2:Er3+/Yb3+ on the top of TiO2 film is further treated with LiI contained acetonitrile solution. Cost effective, platinum-free counter electrode (CE) made with Tin sulfide (SnS), carbon and its composite are sandwiched with surface treated photoelectrode for DSSCs fabrication. The enhanced power conversion efficiency (PCE) 9.52% for LiI treated CeO2:Er3+/Yb3+ based DSSC is witnessed with composite CE is higher than Pt based DSSC (8.32%).

Greatly enhanced power conversion efficiency of hole-transport-layer-free perovskite solar cell via coherent interfaces of perovskite and carbon layers

Abstract The interfacial contact between a perovskite and a carbon layer significantly affects the photovoltaic performance of a paintable and carbon-based hole transport material (HTM)-free perovskite solar cell (PSC). However, the detailed mechanism of the performance degradation, with regard to the carrier dynamics behavior at the perovskite/carbon interface, has not been elucidated yet. In this study, the improved interface of the perovskite/carbon was designed via a newly carbon electrode with nanosized carbon black and carbon fibers. Meanwhile, the modified Mott-Schottky analysis is conducted to study the carrier dynamics in the coherent and sparsely contacting interfaces, revealing that the unrestricted excitons in the nanoscale non-contact region of the coherent interface can be separated and then drove to be transported by the lateral built-in electric field. Furthermore, the HTM-free PSC via improved material design and fabrication by using a bilayer carbon electrode (coherent layer and conductive layer) results in an enhanced champion efficiency of 14.1%.

Tuning the optoelectronic properties of Subphthalocyanine (SubPc) derivatives for photovoltaic applications

Abstract In the quest of enhanced power conversion efficiency (PCE) and device performance of small molecule based organic solar cells, four new acceptor-donor-acceptor (A-D-A) type novel chromophores (Y1-Y4) have been designed with subphthalocyanine (SubPc) as a common donor and different benzene bridged end-capped 2-methylenemalononitrile (A1), 6-methylene-2-thioxo-1,3-thiazinan-4-one (A2), 2-(2-methylene-3-oxo-2,3-dihydro-1H-inden-1ylidene) malononitrile (A3) and 5-methylene-2-thioxothiazolidin-4-one (A4) acceptor groups. Photovoltaic and quantum chemical parameters of Y1-Y4 were computed through DFT and TD-SCF using selected B3LYP hybrid functional. Next, the parameters affecting chemical reactivity, opto-electronic properties, charge mobility and exciton dynamics of Y1-Y4 were characterized through calculations of frontier molecular orbitals, absorption profiles, density of states (DOS) and transition density matrix (TDM) respectively. The results imply that the designed candidates (Y1-Y4) proved more proficient in executing the afore-said parameters compared to R (reference). Amongst all, Y3 surpassed in exhibiting the best efficiency with highest absorption value (667 nm) and lowest band gap (2.12 eV). Moreover, low reorganization energies, high dipole moment and comparable values of open circuit voltage (Voc) make these molecules a useful tactic for use in small molecule based organic solar devices.

Improvement of light-harvesting efficiency of amorphous silicon solar cell coated with silver nanoparticles anchored via (3-mercaptopropyl) trimethoxysilane

Owing to small size effect and large surface area, silver nanoparticles (Ag NPs) exhibit special physical properties and are widely used in different applications. One of the significant applications is that Ag NPs can be coated on the glass surface of solar cell to increase the light-harvesting efficiency of solar cell due to the plasmonic resonance and scattering effect. In this study, Ag NPs used for the coating of solar cells were synthesized via a chemical reduction method. The effect of the concentration of sodium borohydride (NaBH4) as reducing agent and 1-dodecanethiol (DDT) as capping agent on the size and shape of Ag NPs synthesized have been investigated. The synthesized Ag NPs were characterized using UV–vis spectroscopy, X-ray diffraction, energy-dispersive X-ray spectrometry and ATR-FTIR spectroscopy; while the particle size, morphology and topology of Ag NPs were examined by scanning electron microscopy and atomic force microscopy. By coating the glass surface of amorphous silicon solar cells with a uniform array of Ag NPs with the particle size of > 350 nm, a power conversion efficiency (PCE) enhancement of approximately 41% has been achieved. (3-mercaptopropyl) trimethoxysilane (MPTMS) was used as the adhesion promoter to anchor Ag NPs on the silicon surface of solar cells. With 7% of MPTMS, the array of Ag NPs formed on the glass surface was found being the most evenly distributed with a densely packed surface coverage, which resulted in 46% of PCE enhancement of the silicon solar cells.

Microwave synthesis and analysis of Sb2S3 nanostructures as IR photon-absorber and counter electrode for the design of symmetric solar cells

Sb2S3 nanostructures of orthorhombic phase are synthesized by a facile microwave irradiation technique by optimizing the morphology. These are employed as the infrared photon absorber of the solar spectrum, and J-V results confirm that Poly Vinyl Pyrrolidone (PVP) and citric treated Sb2S3 nanowires/nanorods deliver the highest JSC of ~3.45 mA/cm2, η of ~0.48% and 3.22 mA/cm2, η of ~0.35% respectively. The samples are employed as the counter electrode under TiO2/N719/(I-/I3-), and among all, PVP treated Sb2S3 yield the highest JSC of ~11.2 mA/cm2 and η of ~4.6%. This enhancement in Power Conversion Efficiency (PCE) is analyzed by impedance spectroscopy. Apart from photon-absorbing property, cyclic voltammetry measurements reveal that Sb2S3 acquire better electrocatalytic activity and charge-transfer ability under I3-/I- and polysulfide medium. This superior electrocatalytic activity will be useful in the design of symmetric solar cells in the future where this nanostructure can act as a sensitizer as well as counter electrode in a single cell.

Improved Performance of Ternary Solar Cells by Using BODIPY Triads.

Two boron dipyrromethene (BODIPY) triads, namely BODIPY-1 and BODIPY-2, were synthesized and incorporated with poly-3-hexyl thiophene: (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) P3HT:PCBM. The photovoltaic performance of BODIPY:P3HT:PCBM ternary solar cells was increased, as compared to the control binary solar cells (P3HT:PCBM). The optimized power conversion efficiency (PCE) of BODIPY-1:P3HT:PCBM was improved from 2.22% to 3.43%. The enhancement of PCE was attributed to cascade charge transfer, an improved external quantum efficiency (EQE) with increased short circuit current (Jsc), and more homogeneous morphology in the ternary blend.

Crystallisation control of drop-cast quasi-2D/3D perovskite layers for efficient solar cells

Introducing layered quasi-2D perovskite phases into a conventional 3D perovskite light-absorbing matrix is a promising strategy for overcoming the limited environmental stability of 3D perovskite solar cells. Here, we present a simple drop-casting method for preparing hybrid perovskite films comprising both quasi-2D and quasi-3D phases, formed using phenylethylammonium or iso-butylammonium as spacer cations. The film morphology, phase purity, and crystal orientation of the hybrid quasi-2D/3D perovskite films are improved significantly by applying a simple N2 blow-drying step, together with inclusion of methylammonium chloride as an additive. An enhanced power conversion efficiency of 16.0% is achieved using an iso-butylammonium-based quasi-2D/3D perovskite layer which, to our knowledge, is the highest recorded to date for a quasi-2D/3D perovskite solar cells containing a non-spin-cast perovskite layer prepared under ambient laboratory conditions.

Photoelectrochromic Devices with Enhanced Power Conversion Efficiency.

In the present work, we propose a new architecture for partly covered photoelectrochromic devices with a modified anode layout, so that the TiO2 film is deposited first on the substrate, covering a small part of its surface, followed by the WO3 film that covers the remaining device area. As a result, the TiO2 film can be subjected to the proper thermal and chemical treatment without affecting the electrochromic performance of the WO3 film. The proposed design led to photoelectrochromic (PEC) devices with a power conversion efficiency (PCE) four times higher than that of typical partly covered devices, with a measured maximum of 4.9%. This, in turn, enabled a reduction in the total area covered by the photovoltaic unit of the devices by four times (to 5% from 20%), thus reducing its visual obstruction, without affecting the depth, uniformity and speed of coloration. A detailed study of the parameters affecting the performance of the new devices revealed that, with the cover ratio decreasing, PCE was increasing. The photocoloration efficiency also exhibited the same trend for cover ratio values below 15%. Storage of the devices in short circuit conditions was found to accelerate optical reversibility without affecting their photovoltaic and optical performance.

Graphitic carbon nitride quantum dots (g-C3N4) to improve photovoltaic performance of polymer solar cell by combining Förster resonance energy transfer (FRET) and morphological effects

In this study, multifunctionality of graphitic carbon nitride quantum dots (g-C3N4 QDs) have been explored as a photovoltaic booster for polymer solar cell. Facile synthesis method of g-C3N4 QDs using organic solvent like o-dichlorobenzene which is commonly used for cell fabrication, has been demonstrated. Photovoltaic effect formation and various effects of QDs on energy transfer, carrier transport and nanoscale film morphology of the devices have been investigated thoroughly by incorporating g-C3N4 QDs as a third component into a well-established material combination of P3HT: PC71BM blend films. While systematic variation of device performances was observed with varying concentration of QDs, at an optimal concentration of 2%, almost 40% performance improvement was achieved compared to the pristine devices. The g-C3N4 QDs were found to assist Förster resonance energy transfer (FRET) between the QDs and host polymer, improving overall energy harvesting capability of the devices. The emission spectra of g-C3N4 QDs (λEms = 400–550) and absorption spectra of P3HT (λAbs = 400–600) were found to have overlapping features which enabled the QDs to transfer ultraviolet region photon energy to P3HT. The g-C3N4 QDs were also found to be favorable for maintaining nanoscale phase segregation of the active layer with improved crystallinity which is crucial for efficient exciton dissociation and faster charge extraction. The enhanced power conversion efficiency thus attributed to the combined consequences of improved morphology and FRET effect. This study opens new prospects for developing high-efficiency solution processable photovoltaic devices using g-C3N4 QDs as the third component of the active layer.

Groups-dependent phosphines as the organic redox for point defects elimination in hybrid perovskite solar cells

Abstract Lead (Pb)0 and iodine (I)0 point defects generated during perovskite solar cell (PSC) fabrication and photoconversion form deep band energy levels as the carriers’ recombination centers. These defects not only deteriorate device efficiency, but also facilitate chemical degradation with ion migration, resulting in restricted device lifetime. Herein, we present a novel type of phosphines as the point defects stabilizer for hybrid perovskite solar cells with enhanced performances. Three phosphines with varied side groups of tributyl, trioctyl and triphenyl are exampled as the dopants in perovskite films. The group dependent redox properties were observed in the perovskite film, dependent on their molecular weights and steric hinderances of phosphines. The partially oxidized tributyl phosphine (TBUP) with additional tributyl phosphine oxides (TBPO) is efficient in reduction of lead (Pb)0 and iodine (I)0 concentrations during the device fabrication and operation. The device with TBUP-TBPO pair showed enhanced power conversion efficiency (PCE) to 20.48% and maintain 91.7% of their initial PCEs after 500 h at 65 °C thermal annealing. Thus, this work presents an efficient route of utilize the phosphine species to reduce point defects in the perovskite film, which promoting further development of novel phosphorous additives with defects stabilization, interface passivation and encapsulation for low-cost solution processed PSCs.