JIALINGBO

Publication date: 15 May 2021

Source: Chemical Engineering Journal, Volume 412

Author(s): Wenxiao Zhang, Xiaodong Li, Xiuxiu Feng, Xiaoyan Zhao, Junfeng Fang

Harmful UV light and surface defects accelerate the degradation of perovskite solar cells (PSCs). A tautomeric “sunscreen” molecule can be used to protect the PSC from UV degradation and enable molecular defect passivation (defect formation energy: −1.35 eV) through interactions between functional groups and defects. This strategy provides high‐efficiency PSCs with long‐term UV stability.

Abstract

UV light always does great harm to perovskite solar cells, relentlessly degrading perovskites and shortening the lifetime of perovskite devices. Meanwhile, surface defects in perovskite films further accelerate the degradation process and serve as nonradiative charge recombination centers to deteriorate device efficiency. Herein, we demonstrate that a “sunscreen” molecule, 2‐hydroxy‐4‐methoxybenzophenone, not only protects the perovskite solar cell from UV degradation but also enables molecular defect passivation through interaction between functional groups and defects by molecular tautomerism under UV light illumination. Therefore, the sunscreen strategy efficiently enhances the UV endurance of PSCs and improves defect formation energy to −1.35 eV. The perovskite solar cell with sunscreen (sunscreen PSC) exhibits outstanding efficiencies of up to 23.09 % (0.04 cm²) and 19.73 % (1.00 cm²) as well as long‐term UV (UVa: 365 nm and UVb: 285 nm) stability.

Over 23% efficiency is achieved using a stabilized phenyl‐C₆₁‐butyric acid methyl ester (PCBM):bathophenanthroline (Bphen) interlayer in SnO₂‐based perovskite solar cells, which can retain over 92% of their initial efficiency after 1000 h continuous illumination of maximum power point tracking at 60 °C.

Abstract

It is crucial to make perovskite solar cells sustainable and have a stable operation under natural light soaking before they become commercially acceptable. Herein, a small amount of the small molecule bathophenanthroline (Bphen) is introduced into [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester and it is found that Bphen can stabilize the C₆₀‐cage well through formation of much more thermodynamically stable charge‐transfer complexes. Such a strengthened complex is used as an interlayer at the in‐light perovskite/SnO₂ side to achieve a champion device with efficiency of 23.09% (certified 22.85%). Most importantly, the stability of the resulting devices can be close to meeting the requirements of the International Electrotechnical Commission 61215 standard under simulated UV preconditioning and light‐soaking testing. They can retain over 95% and 92% of their initial efficiencies after 1100 h UV irradiation and 1000 h continuous illumination of maximum power point tracking at 60 °C, respectively.

An ionic liquid, 1,3‐dimethyl‐3‐imidazolium hexafluorophosphate (DMIMPF₆), was used to passivate a perovskite to decrease the defects of Pb‐cluster and Pb‐I antisite, thereby reducing the energy barrier between the perovskite and hole transport layer. A perovskite solar cell attained a 23.25 % efficiency with a high stability due to hydrophobic DMIMPF₆.

Abstract

Surface defects have been a key constraint for perovskite photovoltaics. Herein, 1,3‐dimethyl‐3‐imidazolium hexafluorophosphate (DMIMPF₆) ionic liquid (IL) is adopted to passivate the surface of a formamidinium‐cesium lead iodide perovskite (Cs_0.08FA_0.92PbI₃) and also reduce the energy barrier between the perovskite and hole transport layer. Theoretical simulations and experimental results demonstrate that Pb‐cluster and Pb‐I antisite defects can be effectively passivated by [DMIM]⁺ bonding with the Pb²⁺ ion on the perovskite surface, leading to significantly suppressed non‐radiative recombination. As a result, the solar cell efficiency was increased to 23.25 % from 21.09 %. Meanwhile, the DMIMPF₆‐treated perovskite device demonstrated long‐term stability because the hydrophobic DMIMPF₆ layer blocked moisture permeation.

Inorganic perovskite CsPbI₂Br is applied to prepare high‐performance semitransparent perovskite solar cells (ST‐PSCs). (Chloromethylene)‐dimethylammonium chloride as an additive is introduced into the perovskite precursor to favor high‐quality CsPbI₂Br perovskite films. Through optimizing the perovskite film, interface, and electrode type, the efficiency of the ST‐PSC reaches 14.01% and 10.36% under an average visible transmittance (AVT) of 31.7% and 40.9%, respectively.

Abstract

Thanks to the tunable bandgap and excellent photoelectric characteristics, perovskites have been widely used in semitransparent solar cells (ST‐SCs). Most works present unsatisfactory power conversion efficiencies (PCEs) through reducing the thickness of the perovskite films because there is a trade‐off between PCE and average visible transmittance (AVT). As a consequence, most PCEs are less than 12% when the AVT is higher than 20% due to the limited voltage (V _oc) and short‐circuit current (J _sc). Herein, a strategy of intermediate adduct (IMAT) engineering is developed to improve the film quality of the inorganic perovskite CsPbI₂Br, which is a challenging issue to limit its performance of efficiency and stability. A normal n–i–p‐structured PSC based on the optimal CsPbI₂Br film delivers a PCE of 16.02% with excellent stability. Furthermore, through optimizing the electrode type and interface, the ST‐PSC shows a high V _oc larger than 1.2 V and the PCE reaches 14.01% and 10.36% under an AVT of 31.7% and 40.9%, respectively. This is the first demonstration of a CsPbI₂Br ST‐PSC, and it outperforms most of other types of perovskites.

Two sequentially deposited SnO₂ layers doped with a low and a high amount of ammonium chloride, respectively, boost the open‐circuit voltage and fill factor of perovskite solar cells. The main effect of the novel electron transport layer is a change in the energy level alignment with the perovskite interface leading to decreased carrier recombination.

Abstract

Tin oxide (SnO₂) is an emerging electron transport layer (ETL) material in halide perovskite solar cells (PSCs). Among current limitations, open‐circuit voltage (V _OC) loss is one of the major factors to be addressed for further improvement. Here a bilayer ETL consisting of two SnO₂ nanoparticle layers doped with different amounts of ammonium chloride is proposed. As demonstrated by photoelectron spectroscopy and photophysical studies, the main effect of the novel ETL is to modify the energy level alignment at the SnO₂/perovskite interface, which leads to decreased carrier recombination, enhanced electron transfer, and reduced voltage loss. Moreover, X‐ray diffraction reveals reduced strain in perovskite layers grown on bilayer ETLs with respect to single‐layer ETLs, further contributing to a decrease of carrier recombination processes. Finally, the bilayer approach enables the more reproducible preparation of smooth and pinhole‐free ETLs as compared to single‐step deposition ETLs. PSCs with the doped bilayer SnO₂ ETL demonstrate strongly increased V _OC values of up to 1.21 V with a power conversion efficiency of 21.75% while showing negligible hysteresis and enhanced stability. Moreover, the SnO₂ bilayer can be processed at low temperature (70 °C), and has therefore a high potential for use in tandem devices or flexible PSCs.

Harmful UV light and surface defects accelerate the degradation of perovskite solar cells (PSCs). A tautomeric “sunscreen” molecule can be used to protect the PSC from UV degradation and enable molecular defect passivation (defect formation energy: −1.35 eV) through interactions between functional groups and defects. This strategy provides high‐efficiency PSCs with long‐term UV stability.

Abstract

UV light always does great harm to perovskite solar cells, relentlessly degrading perovskites and shortening the lifetime of perovskite devices. Meanwhile, surface defects in perovskite films further accelerate the degradation process and serve as nonradiative charge recombination centers to deteriorate device efficiency. Herein, we demonstrate that a “sunscreen” molecule, 2‐hydroxy‐4‐methoxybenzophenone, not only protects the perovskite solar cell from UV degradation but also enables molecular defect passivation through interaction between functional groups and defects by molecular tautomerism under UV light illumination. Therefore, the sunscreen strategy efficiently enhances the UV endurance of PSCs and improves defect formation energy to −1.35 eV. The perovskite solar cell with sunscreen (sunscreen PSC) exhibits outstanding efficiencies of up to 23.09 % (0.04 cm²) and 19.73 % (1.00 cm²) as well as long‐term UV (UVa: 365 nm and UVb: 285 nm) stability.

Over 23% efficiency is achieved using a stabilized phenyl‐C₆₁‐butyric acid methyl ester (PCBM):bathophenanthroline (Bphen) interlayer in SnO₂‐based perovskite solar cells, which can retain over 92% of their initial efficiency after 1000 h continuous illumination of maximum power point tracking at 60 °C.

Abstract

It is crucial to make perovskite solar cells sustainable and have a stable operation under natural light soaking before they become commercially acceptable. Herein, a small amount of the small molecule bathophenanthroline (Bphen) is introduced into [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester and it is found that Bphen can stabilize the C₆₀‐cage well through formation of much more thermodynamically stable charge‐transfer complexes. Such a strengthened complex is used as an interlayer at the in‐light perovskite/SnO₂ side to achieve a champion device with efficiency of 23.09% (certified 22.85%). Most importantly, the stability of the resulting devices can be close to meeting the requirements of the International Electrotechnical Commission 61215 standard under simulated UV preconditioning and light‐soaking testing. They can retain over 95% and 92% of their initial efficiencies after 1100 h UV irradiation and 1000 h continuous illumination of maximum power point tracking at 60 °C, respectively.

Perovskite light‐emitting diodes (PeLEDs) are remarkable candidates for the next‐generation display owing to its pure color purity and high efficiency. This review systematically introduces strategies to enhance the efficiencies of PeLEDs in terms of device structural engineering. Hole and electron injection, charge balance, morphology control, defect passivation, and other factors of each interlayer are discussed.

Abstract

Metal halide perovskite (MHP) light‐emitting diodes (LEDs) have been widely studied and have been reached to >20% external quantum efficiency, owing to their attractive characteristics (e.g., solution processability, tunable bandgap and extremely high color purity, high mobility). During the rapid development of perovskite light‐emitting diodes (PeLEDs), modifying the device architecture has been widely studied as well as improving the crystal quality of MHP to achieve near‐unity photoluminescence quantum yield. However, efforts in device architecture engineering have received less attention despite their significance. Here, strategies are reviewed to enhance the efficiency of PeLEDs in terms of the device engineering by interfacial charge injection/transport, exciton‐quenching blocking, and defect passivation layers for enhancing radiative electron–hole recombination. Strategies are systematically classified for each layer in PeLEDs and discussed the synergetic effect between different strategies. Perspective is also provided on future research on PeLEDs focusing on their architecture.

Sunlight can be converted to electricity via solar cells, with which then light can be generated the other way around. In this regard, skyscrapers performing light show during night or the bright Karst landscape under the ground are exemplified, echoing the geometry of the TiO₂ nanopillars which are fabricated via a low‐temperature dry process and work as the efficient electron‐transporting layer in flexible perovskite solar cells. More details can be found in article number 2001512 by Zhifeng Huang, Zijian Zheng, and co‐workers.

Perovskite nanocrystals (PCNs) have great application potential in the field of photocatalysis, but their inherent shortcomings are hindering development. The construction of heterostructures is one of the most effective ways to solve these problems. Herein, this article systematically categorizes the effective construction strategies of PCNs heterostructures for perovskites’ urgent issues and gives a future outlook.

Perovskite nanocrystals (PNCs) have recently emerged as a new type of promising photocatalytic semiconductor due to their unique photoelectrochemical properties, including tunable bandgap and crystal structure, entire visible spectral response, and versatile chemical processability. However, under practical circumstance, this type of pure‐phase PNCs photocatalyst demonstrates poor stability, limited light utilization, and high carrier recombination, resulting in low solar power conversion efficiency and inferior catalytic activity. To address these issues, extensive research efforts have been devoted to developing PNCs‐based heterostructures. Thus, a perspective on the development of PNCs‐based heterophotocatalysts is timely. In this Review, the progress of PNCs‐based heterophotocatalysts is presented starting from fundamental properties (i.e., crystal and bandgap structure, photoelectronic properties, etc.) to state‐of‐the‐art applications with a focus on stability improving, dispersion enhancing, and interfacial charge carrier dynamic optimizing. Critical insights are further provided into the existing challenges and prospects for high‐quality PNCs‐based heterostructures in advanced photocatalytic applications.

Sodium diethyldithiocarbamate (NaDEDTC) as processing agent enhances the open‐circuit voltage of methylammonium lead triiodide perovskite solar cells. DEDTC modulates film formation, improves the charge transfer between the hole transporting layer and the perovskite, and reduces nonradiative recombination. However, it is not incorporated in the perovskite or present as a surface ligand.

The incorporation of additives to modulate the properties of metal halide perovskite thin films has become a successful approach in improving the power conversion efficiency of perovskite‐based solar cells. Herein, the beneficial use of sodium diethyldithiocarbamate (NaDEDTC) as processing agent in improving the open‐circuit voltage of methylammonium lead triiodide perovskite solar cells is reported. DEDTC reduces the rate of perovskite crystallization. Absorption and emission spectra show that the optical bandgap of the perovskite films remain essentially unchanged and X‐ray diffraction reveals the formation of preferentially oriented crystallites independent of the use of DEDTC. The use of DEDTC, however, results in a decrease in nonradiative decay as inferred from a two order of magnitude increase in electroluminescence efficiency, explaining the increased open‐circuit voltage. Fourier‐transform infrared spectroscopy, nuclear magnetic resonance, and X‐ray photoelectron spectroscopy show that the DEDTC ligand is not present after the film processing. Therefore, DEDTC modulates film formation but is not incorporated in the perovskite or present as a surface ligand. Sodium ions, on the contrary, are incorporated in the perovskite layer.

An alkyl linker‐free, fully conjugated aromatic 2,2′‐biimidazolium cation‐based quasi‐2D perovskite shows enhanced hole and electron mobilities and subsequently improved performance compared with the well‐known organic cation phenylethylammonium‐based quasi‐2D perovskite. A high power conversion efficiency (PCE) of 11.4% (n = 5) is achieved with random‐orientated crystal growth.

Quasi‐2D perovskites are attractive because of their improved stability compared with 3D perovskites counterparts; however, they suffer from poor performance due to the insulating organic cation spacers. To resolve this issue, a strategy of replacing the insulating spacer with conducting spacer is proposed which successfully converts the spacer from a charge‐transporting “barrier” to charge‐transporting “bridge.” Specifically, an alkyl linker‐free, fully conjugated aromatic 2,2′‐biimidazolium (BIDZ) cation is introduced as a spacer to compose quasi‐2D perovskites. Density functional theory (DFT) simulation results show that the lowest unoccupied molecular orbital (LUMO) level localizes on BIDZ and the highest occupied molecular orbital (HOMO) level is on the perovskite. However, both HOMO and LUMO levels localize on perovskite slabs for the well‐known phenethylammonium (PEA)‐based 2D perovskites. The strong electronic coupling between BIDZ and 3D perovskite slabs improves carrier mobilities even for a low‐weak‐crystallinity and random‐orientated quasi‐2D perovskite film. As a result, a remarkable power conversion efficiency up to 11.4% (n = 5) is achieved, which is much higher than that of PEA‐based random‐orientated quasi‐2D perovskites with the same processing condition (6.5%). The strategy paves the way to highly efficient and stable quasi‐2D perovskites solar cells through designing new organic spacer cations.

A multi-functional interfacial layer composed of a mixture of a poly(oxyethylene tridecyl ether) surfactant and an ethanolamine compound is introduced between a CH₃NH₃PbI₃ perovskite light-harvesting layer and a nickel oxide hole transport layer. Due to the improved film-forming and hole-extracting capabilities, excellent photovoltaic performance is successfully realized together with reduced recombination losses.

Abstract

Recently, hybrid organic–inorganic perovskite solar cells (PVSCs) have attracted significant attention owing to their simple solution processability and high efficiency for the next generation of low-cost solar cell technology. Herein, a multi-functional interfacial layer (IFL) composed of a mixture of poly(oxyethylene tridecyl ether) (PTE) and ethanolamine (EA) is introduced between a CH₃NH₃PbI₃ perovskite light-absorbing layer and a nickel oxide (NiO _x ) hole transport layer to improve the photovoltaic (PV) performance of PVSCs. With the solution-coated IFL of mixed PTE:EA, a highly improved film-forming capability of the perovskite layer is realized together with large-sized grains and fewer film defects. Moreover, the IFL also improved the charge carrier separation and hole-extraction capabilities at the interface between the CH₃NH₃PbI₃ and the NiO _x layers. The results here successfully demonstrate that the CH₃NH₃PbI₃ PVSC with IFL exhibits greatly improved PV performance, in this case a much higher power conversion efficiency (15.1%), greatly exceeding that (12.3%) of a reference device without an IFL. The author's study demonstrates that a multi-functional mixed IFL can be used as a solid foundation for efficient and cost-effective PVSCs, thus providing a platform for the realization of a new generation of highly efficient solution-processable PVSCs.

The discussion focuses on how the crystallographic properties and the structure of the Ruddlesen–Popper perovskite impact the efficiency of the solar cells. The strategies for film processing and material design in past studies and the potential research directions in the future are discussed.

Abstract

Metal halide Ruddlesen–Popper perovskite solar cells (RPPSCs) have attracted a great deal of attention in the research community due to their excellent stability over the 3D counterparts. In 2014, the first RPPSC was reported achieving a power conversion efficiency (PCE) of about 4.7%. To date, this type of solar cells reach a PCE exceeding 18% on lab scale. In this essay, distil strategies to further improve the PCE of RPPSCs are discussed. First, the unique physical properties of RPP are discussed to highlight the importance of film processing and material design, and then the factors that are limiting RPPSCs with special focus on the crystallographic and charge transport properties are addressed. Finally, the opportunities for RPPSCs are discussed, and opinions are provided regarding how to further improve the performance of these devices and on strategies which may advance the technology toward its industrial exploitation.

Sulfur can passivate trap states, suppress charge recombination and inhibition migration, thereby enhancing the stability of perovskite solar cells (PSCs). PbS bonds provide new channels for carrier extraction. This review summarizes the sulfur‐based compounds utilized in PSCs by their functions in each layer, which can help others understand the intrinsic phenomena of sulfur‐based PSCs and motivate additional investigations.

In the past decade, organic–inorganic hybrid perovskite solar cells (PSCs) have begun to be increasingly studied worldwide owing to the superior properties of perovskite material. However, some issues have delayed their commercialization, such as their long‐term stability, cost reduction, scale‐up ability, and efficiency. The introduction of sulfur to PSCs can relieve the above issues because sulfur can passivate interfacial trap states, suppress charge recombination, and inhibit ion migration, thereby enhancing the stability of PSCs. Furthermore, PbS bonds provide new channels for carrier extraction. Herein, the sulfur‐based compounds utilized in PSCs are summarized and classified according to their functions in the different layers of PSCs. The results indicate that these sulfur‐based compounds have efficiently promoted the commercialization of PSCs. It is hoped that this review can help others understand the intrinsic phenomena of sulfur‐based PSCs and motivate additional investigations.

A series of donor–π–acceptor porphyrins coded as CS0, CS1, and CS2 that can effectively passivate the perovskite surface, increase V _OC and FF, reduce the hysteresis effect, enhance power conversion efficiency to be higher than 22%, and improve the device stability have been developed.

Abstract

In recent years, hybrid perovskite solar cells (PSCs) have attracted much attention owing to their low cost, easy fabrication, and high photoelectric conversion efficiency. Nevertheless, solution‐processed perovskite films usually show substantial structural disorders, resulting in ion defects on the surface of lattice and grain boundaries. Herein, a series of D–π–A porphyrins coded as CS0, CS1, and CS2 that can effectively passivate the perovskite surface, increase V _OC and FF, reduce the hysteresis effect, enhance power conversion efficiency to be higher than 22%, and improve the device stability is developed. The results in this study demonstrated that the donor–π–acceptor type porphyrin derivatives are promising passivators that can improve the cell performance of PSCs.

An in‐situ formed polymeric interlayer enables enhanced photovoltaic performance of the methylammonium‐, cesium‐, and bromide‐free perovskite solar cells with superior photo‐ and thermal‐stability. The polymeric interlayer promotes growth of perovskite crystals with reduced defect density and improves the contact between the perovskite and hole transporting layers to assists in photo‐excited charge extraction.

Abstract

The vast majority of high‐performance perovskite solar cells (PSCs) are based on multi‐cation mixed‐anion compositions incorporating methylammonium (MA) and bromide (Br). Nevertheless, the thermal instability of MA and the tendency of mixed halide compositions to phase segregate limit the long‐term stability of PSCs. However, reports of MA‐free and/or Br‐free compositions are rare in the community since their performance is generally inferior. Here, a strategy is presented to achieve highly efficient and stable PSCs that are altogether cesium (Cs)‐free, MA‐free and Br‐free. An antisolvent quenching process is used to in‐situ deposit a polymeric interlayer to promote the growth of phase‐pure formamidinium lead tri‐iodide perovskite crystals with reduced defect density and to assist in photo‐excited charge extraction. The PSCs developed are among the best‐performing reported for such compositions. Moreover, the PSCs show superior stability under continuous exposure to both illumination and 85 °C heat.

Nature Nanotechnology, Published online: 11 February 2021; doi:10.1038/s41565-021-00848-w

A Ni phthalocyanine (NiPc) decorated by four methoxyethoxy units with a strong intramolecular electric field is prepared and used as hole‐transporting materials (HTMs) in perovskite solar cells (PSCs). The best PSCs with NiPc as dopant‐free HTM show a record efficiency of 21.23 % (certified 21.03 %). The PSCs also exhibit the excellent stability.

Abstract

Low conductivity and hole mobility in the pristine metal phthalocyanines greatly limit their application in perovskite solar cells (PSCs) as the hole‐transporting materials (HTMs). Here, we prepare a Ni phthalocyanine (NiPc) decorated by four methoxyethoxy units as HTMs. In NiPc, the two oxygen atoms in peripheral substituent have a modified effect on the dipole direction, while the central Ni atom contributes more electron to phthalocyanine ring, thus efficiently increasing the intramolecular dipole. Calculation analyses reveal the extracted holes within NiPc are mainly concentrated on the phthalocyanine core induced by the intramolecular electric field, and further to be transferred by π‐π stacking space channel between NiPc molecules. Finally, the best efficiency of PSCs with NiPc as dopant‐free HTMs realizes a record value of 21.23 % (certified 21.03 %). The PSCs also exhibit the good moisture, heating and light stabilities. This work provides a novel way to improve the performance of PSCs with free‐doped metal phthalocyanines as HTMs.

An ionic liquid, 1,3‐dimethyl‐3‐imidazolium hexafluorophosphate (DMIMPF₆), was used to passivate a perovskite to decrease the defects of Pb‐cluster and Pb‐I antisite, thereby reducing the energy barrier between the perovskite and hole transport layer. A perovskite solar cell attained a 23.25 % efficiency with a high stability due to hydrophobic DMIMPF₆.

Abstract

Surface defects have been a key constraint for perovskite photovoltaics. Herein, 1,3‐dimethyl‐3‐imidazolium hexafluorophosphate (DMIMPF₆) ionic liquid (IL) is adopted to passivate the surface of a formamidinium‐cesium lead iodide perovskite (Cs_0.08FA_0.92PbI₃) and also reduce the energy barrier between the perovskite and hole transport layer. Theoretical simulations and experimental results demonstrate that Pb‐cluster and Pb‐I antisite defects can be effectively passivated by [DMIM]⁺ bonding with the Pb²⁺ ion on the perovskite surface, leading to significantly suppressed non‐radiative recombination. As a result, the solar cell efficiency was increased to 23.25 % from 21.09 %. Meanwhile, the DMIMPF₆‐treated perovskite device demonstrated long‐term stability because the hydrophobic DMIMPF₆ layer blocked moisture permeation.

Publication date: June 2021

Source: Nano Energy, Volume 84

Author(s): Jian Xiong, Zhongjun Dai, Shiping Zhan, Xiaowen Zhang, Xiaogang Xue, Weizhi Liu, Zheling Zhang, Yu Huang, Qilin Dai, Jian Zhang

The mystery of the buried interface in perovskite photovoltaics is deciphered by combining advanced spectroscopy techniques with a lift‐off strategy. The findings open a new avenue to understanding performance losses and thus the design of unique passivation strategies to remove imperfections at the top surfaces and buried interfaces of perovskite photovoltaics, resulting in substantial enhancement in device performance.

Abstract

Understanding the fundamental properties of buried interfaces in perovskite photovoltaics is of paramount importance to the enhancement of device efficiency and stability. Nevertheless, accessing buried interfaces poses a sizeable challenge because of their non‐exposed feature. Herein, the mystery of the buried interface in full device stacks is deciphered by combining advanced in situ spectroscopy techniques with a facile lift‐off strategy. By establishing the microstructure–property relations, the basic losses at the contact interfaces are systematically presented, and it is found that the buried interface losses induced by both the sub‐microscale extended imperfections and lead‐halide inhomogeneities are major roadblocks toward improvement of device performance. The losses can be considerably mitigated by the use of a passivation‐molecule‐assisted microstructural reconstruction, which unlocks the full potential for improving device performance. The findings open a new avenue to understanding performance losses and thus the design of new passivation strategies to remove imperfections at the top surfaces and buried interfaces of perovskite photovoltaics, resulting in substantial enhancement in device performance.