JIANG ZHI XUAN

This work discusses the fundamental understanding of the built‐in potential on efficient operation of the perovskite solar cells (PSCs) and the approach for enhancing the built‐in potential in the PSCs. The outcomes of this work are very inspiring, providing a commercially viable and cost‐effective approach for attaining high‐performance solution‐processable PSCs.

The performance of perovskite solar cells (PSCs) has been improved substantially over the past few years. However, the related fundamental understanding of improving the built‐in potential on the efficiency of the PSCs is still far from adequate. A combination of morphology, charge extraction, and built‐in potential studies would help us to gain an insight on efficient operation of the PSCs. Herein, the effect of the hybrid hole extraction layer (HEL), comprising a mixture of tungsten oxide (WO₃) and poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) (WO₃–PEDOT:PSS), on the growth of the perovskite photoactive layer and built‐in potential in PSCs is investigated using structural analyses, photoelectron spectroscopy, and transient photocurrent (TPC) measurements. It shows that the use of hybrid HEL is an effective approach for enhancing the built‐in potential across the photoactive layer in the PSCs, leading to >20% increase in power conversion efficiency as compared to that of a control PSC prepared using a pristine PEDOT:PSS HEL. PSCs with a higher built‐in potential are favorable for efficient cell operation, as manifested by the charge extraction analyses and TPC measurements.

A modified monomolecular layer strategy (m‐MLS) enables high‐quality perovskite films formation on the hydrophobic polymer hole transporting layer (HTL), and minimizes the ohmic loss induced by the HTL. The perovskite solar cells (PSCs) based on m‐MLS‐modified HTL (F‐PSCs) give a superior reproducibility and a champion efficiency of 19.7% with a fill factor of over 80%.

The hole transport materials that interact with the indium tin oxide (ITO) surface can be processed into monomolecular layers (MLs), which often exhibit different surface and electronic properties than their thin‐film counterparts. Herein, it is found that poly[bis(4‐phenyl)(2,4,6‐trimethylphenyl)amine] (PTAA) films (R‐PTAA) can be easily processed into ML (M‐PTAA) due to the van der Waals interaction between ITO and PTAA. However, compared with R‐PTAA, the work function (WF) and conductivity of M‐PTAA are simultaneously reduced by the charge transfer at the ITO/PTAA interface. To address this issue, a modified monomolecular layer strategy (m‐MLS) is developed, where a small amount of 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane (F4TCNQ) is introduced to enhance the interaction force between ITO and PTAA. PTAA treated by m‐MLS (F‐PTAA) has a hydrophilic physical surface, closely matching electronic energy level with the perovskite layer and smaller bulk resistance. As a result, the efficiency and reproducibility of perovskite solar cells (PSCs) are substantially improved. PSCs based on F‐PTAA demonstrated the highest power conversion efficiency (PCE) of 19.7% with a fill factor of over 80%. This study inspires the development of novel interface modification materials, and provides a simple and convenient direction for the fabrication of high‐performance and reproducible inverted PSCs with high fill factors.

This work discusses the fundamental understanding of the built‐in potential on efficient operation of the perovskite solar cells (PSCs) and the approach for enhancing the built‐in potential in the PSCs. The outcomes of this work are very inspiring, providing a commercially viable and cost‐effective approach for attaining high‐performance solution‐processable PSCs.

The performance of perovskite solar cells (PSCs) has been improved substantially over the past few years. However, the related fundamental understanding of improving the built‐in potential on the efficiency of the PSCs is still far from adequate. A combination of morphology, charge extraction, and built‐in potential studies would help us to gain an insight on efficient operation of the PSCs. Herein, the effect of the hybrid hole extraction layer (HEL), comprising a mixture of tungsten oxide (WO₃) and poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) (WO₃–PEDOT:PSS), on the growth of the perovskite photoactive layer and built‐in potential in PSCs is investigated using structural analyses, photoelectron spectroscopy, and transient photocurrent (TPC) measurements. It shows that the use of hybrid HEL is an effective approach for enhancing the built‐in potential across the photoactive layer in the PSCs, leading to >20% increase in power conversion efficiency as compared to that of a control PSC prepared using a pristine PEDOT:PSS HEL. PSCs with a higher built‐in potential are favorable for efficient cell operation, as manifested by the charge extraction analyses and TPC measurements.

A naphthalene diimide based double‐cable conjugated polymer provided a record efficiency of 8.4 % in single‐component organic solar cells. It simultaneously facilitates exciton separation and charge transport via miscibility control.

Abstract

A record power conversion efficiency of 8.40 % was obtained in single‐component organic solar cells (SCOSCs) based on double‐cable conjugated polymers. This is realized based on exciton separation playing the same role as charge transport in SCOSCs. Two double‐cable conjugated polymers were designed with almost identical conjugated backbones and electron‐withdrawing side units, but extra Cl atoms had different positions on the conjugated backbones. When Cl atoms were positioned at the main chains, the polymer formed the twist backbones, enabling better miscibility with the naphthalene diimide side units. This improves the interface contact between conjugated backbones and side units, resulting in efficient conversion of excitons into free charges. These findings reveal the importance of charge generation process in SCOSCs and suggest a strategy to improve this process: controlling miscibility between conjugated backbones and aromatic side units in double‐cable conjugated polymers.

The application of a low frequency alternating electric field on hybrid perovskite can evidently induce irreversible change of grains/crystal domains and distribution of ionic species in the bulk, leading to tunable opto‐electronic properties and significantly increased efficiency in inverted MAPbI₃ cells without additional treatments and impressive intrinsic long‐term and thermal stability in air without encapsulation.

Abstract

With the rapid development of hybrid metal halide perovskites, controlling and understanding their growth processes have become an important but challenging task. In this paper, alternating electric field as an effective modulation method that acts on the intermediate state in perovskite formation under ambient conditions is introduced. The morphology and microstructure of the as‐formed perovskites can be effectively controlled by tuning simple physical parameters such as the frequency and amplitude, which have shown strong impact on the motion of ionic species and thus influences the formation of materials. Furthermore, the optic and electronic properties of the perovskite (such as the band position) can also be easily tuned by the field parameters. Finally, a conversion efficiency of 19.08% can be achieved in MAPbI₃ device without any doping or additional treatment, with impressive ambient and thermal stability without encapsulation. This result has not only illustrated a new physical approach for material fabrication, but also facilitates deeper understanding of the formation mechanism and generally shed light to the development of more devices and materials.

The properties of trap states that limit the performance of hybrid perovskite solar cells and light‐emitting devices are still under much debate. Herein, a unified model is presented, that accurately describes trap‐related and higher‐order charge‐carrier recombination. This work reveals the importance of explicit accounting for charge‐carrier trapping, detrapping and accumulation, and disentangles radiative and nonradiative recombination channels.

Abstract

Trap‐related charge‐carrier recombination fundamentally limits the performance of perovskite solar cells and other optoelectronic devices. While improved fabrication and passivation techniques have reduced trap densities, the properties of trap states and their impact on the charge‐carrier dynamics in metal‐halide perovskites are still under debate. Here, a unified model is presented of the radiative and nonradiative recombination channels in a mixed formamidinium‐cesium lead iodide perovskite, including charge‐carrier trapping, de‐trapping and accumulation, as well as higher‐order recombination mechanisms. A fast initial photoluminescence (PL) decay component observed after pulsed photogeneration is demonstrated to result from rapid localization of free charge carriers in unoccupied trap states, which may be followed by de‐trapping, or nonradiative recombination with free carriers of opposite charge. Such initial decay components are shown to be highly sensitive to remnant charge carriers that accumulate in traps under pulsed‐laser excitation, with partial trap occupation masking the trap density actually present in the material. Finally, such modelling reveals a change in trap density at the phase transition, and disentangles the radiative and nonradiative charge recombination channels present in FA_0.95Cs_0.05PbI_3, accurately predicting the experimentally recorded PL efficiencies between 50 and 295 K, and demonstrating that bimolecular recombination is a fully radiative process.

By identifying the bulk polarization in the magnetic field under photoexcitation conditions, the existence of photoinduced bulk polarization is verified by removing the interferences of photoinduced mobile ions. In addition, the linear/circular polarization modulated photocurrent (ΔJ _sc) measurements indicate that the orbit–orbit interaction between excitons in hybrid perovskites can be tuned by bulk polarization through the dipole moment of organic cations.

Abstract

Photoinduced polarization and orbit–orbit interaction are important issues in hybrid perovskites toward developing optoelectronic functionalities. This paper identifies that photoinduced polarization occurs in hybrid perovskites with mixed‐cation methylammonium (MA)/formamidinium (FA) (MA _x FA_{(1− x )}PbI₃) by measuring bulk polarization at 1 MHz in a magnetic field. Interestingly, when the internal dipole moment is increased upon increasing the MA:FA ratio, the photoinduced dipolar polarization can be substantially enhanced, clarifying the controversial issue of whether photoexcitation can induce a dielectric polarization within dipolar polarization regime in hybrid perovskites. Furthermore, upon increasing photoinduced dipolar polarization, it is found that the intrinsic orbit–orbit interaction between excitons can be increased, revealed by monitoring photocurrent change (ΔJ _sc) upon switching the photoexcitation between linear and circular polarizations. This presents that organic cations are directly involved in the orbit–orbit interaction within band structures. Clearly, the studies provide an insightful understanding of the dipole moment effects on photoinduced dipolar polarization and orbit–orbit interaction between excitons in hybrid perovskites toward controlling the optoelectronic properties.

A dual‐ion‐migration phenomenon and its underlying possible mechanism are reported for the lead‐free double perovskite Cs₂AgBiBr₆, where the diffusive behavior of both Ag and Br contribute significantly to the degradation of the perovskite thin‐film and long‐term operational stability of the Cs₂AgBiBr₆ solar cells.

Abstract

Lead‐free double perovskite Cs₂AgBiBr₆ has attracted increasing research interest in addressing the toxicity and stability challenges confronted by lead halide perovskites. While most of the studies on this Cs₂AgBiBr₆ material have been focusing on photovoltaic performance and potential applications, its long‐term stability and degradation mechanism are well under‐explored. Herein, high‐quality Cs₂AgBiBr₆ thin‐films are developed for lead‐free double perovskite solar cells with a decent efficiency of 1.91%. By exploring the ambient stability of these photovoltaic devices, it is found that the Cs₂AgBiBr₆ exhibits a unique dual‐ion‐migration phenomenon, where Ag and Br ions gradually diffuse through the hole‐transporting layer in the long‐term operation. This phenomenon leads to the degradation of the Cs₂AgBiBr₆ perovskite and subsequent device failure. Theoretical calculations indicate that low formation energies of the Ag and Br vacancies, and low diffusive energy barriers contribute to the dual‐ion‐migration effect. A possible mechanism involving a vacancy‐mediated ion‐migration is proposed to explain this phenomenon. These key findings are essential for halide double perovskites not only in providing a new knowledge base for further addressing the challenge of double perovskite stability, but also in extending their optoelectronic/electronic applications where mixed electronic, ionic and photonic properties may be desired.

Nature Communications, Published online: 20 August 2020; doi:10.1038/s41467-020-17943-6

Blue light-emitting diodes (LEDs) are critical for displays. Employing a large organic cation into a quasi-two dimensional perovskite with green emission, Chu et al. achieve LEDs exhibiting a high external quantum efficiency of 12.1% and stable spectra in the sky-blue region.

Applied Physics Letters, Volume 117, Issue 7, August 2020.
In recent years, organic halide perovskites have attracted increasing attention from scientists. To understand the device's operational mechanism, obtaining their valence band maxima (VBMs) using ultraviolet photoelectron spectroscopy plays a critical role in determining their electronic structures and related energy level alignments. Two methods are commonly used to extract their valence band (VB) edge from either linear or logarithmic intensity scales to reach the agreement with theoretical calculations. However, the consistency behind these two methods is not revealed. In this report, we have quantitatively studied VB edges for CH3NH3PbI3 and CH3NH3PbBr3 single crystals using different photon energies. After considering both their origins of orbital hybridizations and density of state (intensity) distributions at various momentum spaces, it is revealed that precise VBMs from linear scales can be realized. The VBMs obtained from M symmetry points are 1.13 eV away from the Fermi level for CH3NH3PbI3 and 1.29 eV for CH3NH3PbBr3, suggesting that the VBMs (at the R point) are 0.86 eV for CH3NH3PbI3 and 0.89 eV for CH3NH3PbBr3. Our findings explain the mechanism of precisely obtaining VBMs from these halide perovskite single crystals.

Surface doping of a conjugated polymer is drastically modulated by molecular orientation. Face‐on orientation presents more reaction sites for dopant/host interactions, leading to effective charge trap filling facilitated by efficient vertical transport down to the conductive channel. Hole mobility increases by fivefold to 3 cm² V⁻¹ s⁻¹ in the face‐on case, compared to a minimal change in the edge‐on case.

Abstract

Molecular orientation plays a critical role in controlling carrier transport in organic semiconductors (OSCs). However, this aspect has not been explored for surface doping of OSC thin films. The challenge lies in lack of methods to precisely modulate relative molecular orientation between the dopant and the OSC host. Here, the impact of molecular orientation on dopant–host electronic interactions by large modulation of conjugated polymer orientation via solution coating is reported. Combining synchrotron‐radiation X‐ray measurements with spectroscopic and electrical characterizations, a quantitative correlation between doping‐enhanced charge carrier mobility and the Herman's orientation parameter is presented. This direct correlation can be attributed to enhanced charge‐transfer interactions at host/dopant interface with increasing face‐on orientation of the polymer. These results demonstrate that the surface doping effect can be fundamentally manipulated by controlling the molecular orientation of the OSC layer, enabling optimization of carrier transport.

2D perovskites are of great importance to increase both the efficiency and stability of perovskite interfaces. Motivated by the stronger halogen bond interaction, (5FBzAI)₂PbI₄ used as a capping layer in 3D/2D systems self‐organizes with an in‐plane crystal orientation, inducing a reproducible increase of ≈60 mV in the V _oc, and remarkable operational stability.

Abstract

Despite organic/inorganic lead halide perovskite solar cells becoming one of the most promising next‐generation photovoltaic materials, instability under heat and light soaking remains unsolved. In this work, a highly hydrophobic cation, perfluorobenzylammonium iodide (5FBzAI), is designed and a 2D perovskite with reinforced intermolecular interactions is engineered, providing improved passivation at the interface that reduces charge recombination and enhances cell stability compared with benchmark 2D systems. Motivated by the strong halogen bond interaction, (5FBzAI)₂PbI₄ used as a capping layer aligns in in‐plane crystal orientation, inducing a reproducible increase of ≈60 mV in the V _oc, a twofold improvement compared with its analogous monofluorinated phenylethylammonium iodide (PEAI) recently reported. This endows the system with high power conversion efficiency of 21.65% and extended operational stability after 1100 h of continuous illumination, outlining directions for future work.

A new strategy for synergistically improving molecular doping and carrier mobility is proposed by copolymerizing donor–acceptor type and donor–donor type building blocks along polymer backbone. The copolymers show significantly improved mobilities of 1–2 cm² V⁻¹ s⁻¹ at a high doping level while the structural disorder endows a high Seebeck coefficient, indicating a great potential of random copolymer for thermoelectric application.

Abstract

In this work, it is demonstrated that random copolymerization is a simple but effective strategy to obtain new conductive copolymers as high‐performance thermoelectric materials. By using a polymerizing acceptor unit diketopyrropyrrole with donor units thienothiophene and oligo ethylene glycol substituted bithiophene (g₃2T), it is found that strong interchain donor–acceptor interactions ensure good film crystallinity for charge transport, while donor–donor type building blocks contribute to effective charge transfers. Hall effect measurements show that the high electrical conductivity results from increased free carriers with simultaneously improved mobility reaching over 1 cm² V⁻¹ s⁻¹. The synergistic effect of improved molecular doping and carrier mobility, as well as a high Seebeck coefficient ascribed to the structural disorder along polymer chains via random copolymerization, results in an impressive power factor up to 110 µW K⁻² m⁻¹ which is 10 times higher than that of solution‐processed polythiophenes.

The defect in perovskite film is one of the most non‐negligible factors that can attenuate the performances of perovskite solar cell. This work fabricates defects‐reduced perovskite film by using the lead indicator (dithizone) as an additive of perovskite functional layer. The dithizone can retard the crystallization rate of perovskite films, passivate the defects, and enhance the structure stability of perovskite by coordinating with lead atoms. As a result, the device doped with dithizone yields outstanding power conversion efficiency and stability.

In tandem organic photovoltaics, most ultraviolet–visible photons are absorbed by the front sub‐cell, so in the rear sub‐cell, excitons generated on large‐bandgap donors will be reduced significantly. This reduces the conductivity and limits the hole‐transporting property of the rear sub‐cell. An infrared‐absorbing polymer donor is introduced, which provides a second hole‐generation/transporting mechanism to minimize the aforementioned detrimental effects.

Abstract

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 11.7 mA cm⁻² (while retaining the open‐circuit voltage and fill factor) to result in an enhanced power conversion efficiency of 15.1%.

Research on flexible mobile energy‐supply devices will promote the development of the Internet of Things. An embedded metal nickel (Ni)‐mesh transparent conductive electrode is used as a flexible substrate for perovskite solar cells (PSCs). These Ni‐mesh‐based PSCs exhibit excellent electric properties and remarkable environmental and mechanical stability.

Abstract

The rapid development of Internet of Things mobile terminals has accelerated the market's demand for portable mobile power supplies and flexible wearable devices. Here, an embedded metal‐mesh transparent conductive electrode (TCE) is prepared on poly(ethylene terephthalate) (PET) using a novel selective electrodeposition process combined with inverted film‐processing methods. This embedded nickel (Ni)‐mesh flexible TCE shows excellent photoelectric performance (sheet resistance of ≈0.2–0.5 Ω sq⁻¹ at high transmittance of ≈85–87%) and mechanical durability. The PET/Ni‐mesh/polymer poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS PH1000) hybrid electrode is used as a transparent electrode for perovskite solar cells (PSCs), which exhibit excellent electric properties and remarkable environmental and mechanical stability. A power conversion efficiency of 17.3% is obtained, which is the highest efficiency for a PSC based on flexible transparent metal electrodes to date. For perovskite crystals that require harsh growth conditions, their mechanical stability and environmental stability on flexible transparent embedded metal substrates are studied and improved. The resulting flexible device retains 76% of the original efficiency after 2000 bending cycles. The results of this work provide a step improvement in flexible PSCs.

Adding an appropriate amount of Ti₃C₂ into the ZnO electron transport layer (ETL) to change the energy level structure and electron mobility of the ETL and further make the carrier transport balanced is explored. The ZnO/TiC ETL‐based red emitting perovskite nanocrystals light‐emitting diodes exhibit an external quantum efficiency of 17.4%.

Abstract

2D transition metal carbides, nitrides, and carbonitrides called MXenes show outstanding performance in many applications due to their superior physical and chemical properties. Herein, a ZnO–MXene mixture with different contents of Ti₃C₂ is applied as electron transport layers (ETLs) and the influence of the Ti₃C₂ MXene in all‐inorganic metal halide perovskite nanocrystal light‐emitting diodes (perovskite NC LEDs) is explored. The addition of Ti₃C₂ makes more balanced charge carrier transport in LEDs by changing the energy level structure and electron mobility of ETL. Moreover, lower surface roughness is obtained for the ETL, thus guaranteeing uniform distribution of the perovskite NCs layer and further reducing leakage current. As a result, a 17.4% external quantum efficiency (EQE) with low efficiency roll‐off is achieved with 10% Ti₃C₂, which is a 22.5% improvement compared to LEDs without Ti₃C₂.

Nature Photonics, Published online: 17 August 2020; doi:10.1038/s41566-020-0678-x

Perovskite-filled-membranes enable flexible, sensitive and large-area X-ray detectors. The structures are made by infiltrating perovskite solution into porous polymer membranes.

An efficient photon downshifting layer is developed based on ultrasonic spray deposition of a platinum(II) complex, and considerable improvements in both the performance and stability of perovskite solar cells are observed. The photon downshifting layer is demonstrated to be applicable to various types of perovskite solar cells, achieving a maximum device performance of 22.0%.

Abstract

Despite a rapid increase in light harvesting efficiencies, organic–inorganic hybrid perovskite solar cells (PSCs) exhibit relatively inefficient photocurrent generation in the UV region and severe degradation when exposed to UV light and humidity. Herein, to enhance UV and humidity stability as well as photocurrent generating efficiency, a water‐repellent platinum(II) complex, Pt‐F, is developed as a luminescent photon downshifting layer (PDL) for PSCs. The Pt‐F PDL is fabricated on the glass substrate of a PSC using ultrasonic spray deposition, resulting in a considerably higher crystallinity and photoluminescence quantum yield (PLQY) than those fabricated by conventional spin‐coating processes (PLQYs of 77% and 19%, respectively). A maximum device performance of 22.0% is achieved through the addition of a PDL coating to a 21.4% efficient PSC owing to the long‐range photon downshifting effect of Pt‐F, as confirmed by the enhanced spectral response of the device in the UV region. Moreover, remarkable improvements in UV and humidity stability are observed in Pt‐F‐coated PSCs. The versatile effects of the Pt‐F‐based PDL, when fabricated by ultrasonic spray deposition, suggest wide ranging applicability that can improve the performance and stability of other optoelectronic devices.

Three homologous small molecule donors with hydrogen, fluorine, and chlorine substitution afford organic solar cells with efficiencies over 10% in combination with a common acceptor. The chlorinated derivative exhibits a more crystalline nanomorphology with relatively pure domains and provides more than 12% efficiency.

Abstract

Compared to conjugated polymers, small‐molecule organic semiconductors present negligible batch‐to‐batch variations, but presently provide comparatively low power conversion efficiencies (PCEs) in small‐molecular organic solar cells (SM‐OSCs), mainly due to suboptimal nanomorphology. Achieving precise control of the nanomorphology remains challenging. Here, two new small‐molecular donors H13 and H14, created by fluorine and chlorine substitution of the original donor molecule H11, are presented that exhibit a similar or higher degree of crystallinity/aggregation and improved open‐circuit voltage with IDIC‐4F as acceptor. Due to kinetic and thermodynamic reasons, H13‐based blend films possess relatively unfavorable molecular packing and morphology. In contrast, annealed H14‐based blends exhibit favorable characteristics, i.e., the highest degree of aggregation with the smallest paracrystalline π–π distortions and a nanomorphology with relatively pure domains, all of which enable generating and collecting charges more efficiently. As a result, blends with H13 give a similar PCE (10.3%) as those made with H11 (10.4%), while annealed H14‐based SM‐OSCs have a significantly higher PCE (12.1%). Presently this represents the highest efficiency for SM‐OSCs using IDIC‐4F as acceptor. The results demonstrate that precise control of phase separation can be achieved by fine‐tuning the molecular structure and film formation conditions, improving PCE and providing guidance for morphology design.

An efficient photon downshifting layer is developed based on ultrasonic spray deposition of a platinum(II) complex, and considerable improvements in both the performance and stability of perovskite solar cells are observed. The photon downshifting layer is demonstrated to be applicable to various types of perovskite solar cells, achieving a maximum device performance of 22.0%.

Abstract

Despite a rapid increase in light harvesting efficiencies, organic–inorganic hybrid perovskite solar cells (PSCs) exhibit relatively inefficient photocurrent generation in the UV region and severe degradation when exposed to UV light and humidity. Herein, to enhance UV and humidity stability as well as photocurrent generating efficiency, a water‐repellent platinum(II) complex, Pt‐F, is developed as a luminescent photon downshifting layer (PDL) for PSCs. The Pt‐F PDL is fabricated on the glass substrate of a PSC using ultrasonic spray deposition, resulting in a considerably higher crystallinity and photoluminescence quantum yield (PLQY) than those fabricated by conventional spin‐coating processes (PLQYs of 77% and 19%, respectively). A maximum device performance of 22.0% is achieved through the addition of a PDL coating to a 21.4% efficient PSC owing to the long‐range photon downshifting effect of Pt‐F, as confirmed by the enhanced spectral response of the device in the UV region. Moreover, remarkable improvements in UV and humidity stability are observed in Pt‐F‐coated PSCs. The versatile effects of the Pt‐F‐based PDL, when fabricated by ultrasonic spray deposition, suggest wide ranging applicability that can improve the performance and stability of other optoelectronic devices.