Chen Weijie

Unconjugated side‐chain engineering is performed on non‐fullerene small molecule acceptors based on a fused‐benzodithiophene core. Thieno[3,2‐b]thiophene is superior to thiophene and benzene owing to its dual roles of promoting the molecular energy level (δ‐inductive effect) and optimizing the morphology. Thus, organic solar cells based on PBDB‐T:BTTIC‐TT achieve the highest power conversion efficiency of 13.44% among three devices.

Abstract

2D conjugated side‐chain engineering is an effective strategy that is widely utilized to construct benzodithiophene‐based polymers. Herein, an unconjugated side‐chain strategy to design fused‐benzodithiophene‐based non‐fullerene small molecule acceptors (SMAs) via vertical aromatic side‐chain engineering on the ladder‐type core is employed. Three SMAs named BTTIC‐Th, BTTIC‐TT, and BTTIC‐Ph with thiophene, thieno[3,2‐b]thiophene, and benzene, respectively, as side chains, are designed and synthesized. Three SMAs exhibit similar absorption ranges but different lowest unoccupied molecular orbital (LUMO) energy levels due to the different strength of the δ‐inductive effect between vertical aromatic side chains and their electron‐rich core. Organic solar cells based on PBDB‐T:BTTIC‐TT achieve a power conversion efficiency (PCE) of 13.44%, which is higher than the PCE of devices based on PBDB‐T:BTTIC‐Th (12.91%) and PBDB‐T:BTTIC‐Ph (9.14%). The difference in device performance is investigated by electrical and morphological characterizations. A large domain size and different types of π–π stacking are found in the bulk heterojunction layer of PBDB‐T:BTTIC‐Ph blend film, which are detrimental to exciton dissociation and charge transport. Overall, it is demonstrated that when designing unconjugated side chains, thieno[3,2‐b]thiophene is superior to thiophene and benzene through its dual roles of promoting the LUMO energy level and optimizing the morphology. These results shed light on the side‐chain engineering of high‐performance non‐fullerene SMAs.

Nondoped and Ca²⁺‐doped γ ‐CsPbI₃ films are prepared at low temperature (60 °C). The theoretical simulation and experimental results testify that adding Ca²⁺ can lower the total cohesive energy of γ‐CsPbI₃ and yield a more stable γ‐CsPbI₃ film. The Ca²⁺‐doped γ‐CsPbI₃ perovskite solar cells achieve a hysteresis‐free J–V curve and a maximum power conversion efficiency of 9.20%.

Abstract

Inorganic cubic CsPbI₃ perovskite (α‐CsPbI₃) has been widely explored for perovskite solar cells (PSCs) due to its thermal stability and suitable bandgap of 1.73 eV. However, α‐CsPbI₃ usually requires high synthesis temperatures (>320 °C). Additionally, it usually undergoes phase transition to the nonperovskite structure phase (β‐CsPbI₃), which results in poor photoelectric performance in devices. In this study, it is first found that the tortuous 3D CsPbI₃ phase (γ‐CsPbI₃) can be prepared and used for PSCs by solution process without any additive at low temperature (60 °C). The γ‐CsPbI₃ exhibits suitable bandgap of 1.75 eV and favorable photoelectric properties. However, γ‐CsPbI₃ is a metastable phase and easily transforms into β‐CsPbI₃ in ambient moisture. In order to improve the stability of γ‐CsPbI₃, calcium ions (Ca²⁺) with a relatively small radius of 100 pm are used to partially substitute lead ions (119 pm). This research proves that Ca²⁺ can effectively improve the stability of the γ‐CsPbI₃ at room temperature. By optimizing the doping concentration of Ca²⁺ (CsPb_{1− x} Ca _x I₃, x is from 0% to 2%), the Ca²⁺‐doped γ‐CsPbI₃ PSCs achieve a hysteresis‐free J–V curve and a maximum power conversion efficiency (PCE) of 9.20%.

A series of polycyclic aromatic hydrocarbon (PAH) cores with distinct π‐conjugation size are incorporated to construct a new family of fused‐ring electron acceptors (FREAs) via a simple and low‐cost synthetic route. The optoelectronic properties can be fine‐tuned at a molecular level over a wide range, which enables pyrene‐based DTP‐IC‐4Ph achieving a promising power conversion efficiency (PCE) of 10.37% in additive‐free nonfullerene organic solar cells.

Abstract

A series of polycyclic aromatic hydrocarbons (PAHs) with extended π‐conjugated cores (from naphthalene, anthracene, pyrene, to perylene) are incorporated into nonfullerene acceptors for the first time. Four different fused‐ring electron acceptors (FREAs), i.e., DTN‐IC‐2Ph, DTA‐IC‐3Ph, DTP‐IC‐4Ph, and DTPy‐IC‐5Ph, are prepared via simple and facile synthetic procedures, yielding a remarkable platform to study the structure–property relationship for nonfullerene solar cells. With the PAH core being extended systematically, the gradually redshifted absorption with enhanced molar extinction coefficient (ε) is realized, the energy level of the highest occupied molecular orbital is up‐shifted, and the electron mobility is greatly enhanced. Meanwhile, the solubility decreases and the molecular packing becomes strengthened. As a result, with an optimized combination of these characteristics, DTP‐IC‐4Ph attains good solubility, high molar extinction coefficient, complementary absorption, suitable morphology, well‐matched energy levels, as well as efficient charge dissociation and transport in blend film. Consequently, the DTP‐IC‐4Ph‐based solar cells with a donor polymer, poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)‐benzo[1,2‐b:4,5‐b′]dithiophene))‐alt‐(5,5‐(1′,3′‐di‐2‐thienyl‐5′,7′‐bis(2‐ethylhexyl)benzo[1′,2′‐c:4′,5′‐c′]dithiophene‐4,8‐dione))] (PBDB‐T) exhibit a promising power conversion efficiency of 10.37% without any additives, which is close to the best performance achieved in additive‐free nonfullerene solar cells (NFSCs). The results demonstrate that the PAH building blocks have great potential for the construction of novel FREAs for efficient additive‐free NFSCs.

Efficient electron transport layer‐free perovskite solar cells (ETL‐free PSCs) with cost‐effective and simplifed design can greatly promote the large area flexible application of PSCs. Within this review, the recent advancement, key issues, working mechanism, existing problems, and future direction of ETL‐free PSCs are summarized.

Abstract

Perovskite solar cells (PSCs) have shown great potential for photovoltaic applications with their unprecedented power conversion efficiency advancement. Such devices generally have a complex structure design with high temperature processed TiO₂ as the electron transport layer (ETL). Further careful design of device configuration to fully tap the potentials of perovskite materials is expected. Particularly, for the practical application of PSCs, it is crucial to simplify their device structures thus the associated manufacturing process and cost while maintaining their efficiency to be comparable with the conventional devices. But how simple is simple? ETL‐free PSCs promise the simplest structured, thus simple manufacturing processes and low cost large area PSCs in practical applications. They can also help the further exploration of the great potential of perovskite materials and understanding the working principle of PSCs. Within this review, the evolution of the PSC is outlined by discussing the recent advances in the simplification of device configuration and processes for cost effective, highly efficient, and robust PSCs, with a focus on ETL‐free PSCs. Their advancement, key issues, working mechanism, existing problems, and future performance enhancements. This review aims to promote the future development of low cost and robust ETL‐free PSCs toward more efficient power output.

Publication date: 11 July 2019

Source: Chem, Volume 5, Issue 7

Author(s): Francesco Lamberti, Teresa Gatti, Enrico Cescon, Roberto Sorrentino, Antonio Rizzo, Enzo Menna, Gaudenzio Meneghesso, Moreno Meneghetti, Annamaria Petrozza, Lorenzo Franco

The Bigger Picture

Summary

Graphical Abstract

Stability of organic solar cell is enhanced by utilizing robust electron‐transporting layer composed of TiO₂ nanoparticle chelated with phenyl acetylacetone.

Abstract

It is revealed that instability of interface between photoactive layer and electron‐transporting layer (ETL) is one of the causes of the rapid degradation of organic photovoltaics (OPV) performance during initial operation (burn‐in loss) under the light soaking. The stability of OPV is greatly enhanced by applying a robust ETL composed of TiO₂ nanoparticles (TNPs). The TNPs bound with π–π interactive 3‐phenylpentane‐2,4‐dione (TNP–Ph) form more robust ETLs than those bound with van der Waals interactive 3‐methyl‐2,4‐pentanedione TNP (TNP–Me). The OPV with TNP–Ph maintains 73% of its initial power conversion efficiency (PCE) after 1000 h of light soaking, whereas the PCE of OPV with TNP–Me substantially reduces to 25% of initial PCE. The impedance analysis reveals that the burn‐in loss is due to increase of resistance at the TNP ETL/photoactive layer interface during the light soaking. The transmission electron microscopy analysis shows that the TNP–Ph maintains most clear and robust interface with photoactive layer after the light‐soaking test. This is attributed to the strong π–π interaction between phenyl rings of TNP–Ph. However, the TNP–Me bound with van der Waals interactive organic ligands penetrates the photoactive layer during the light‐soaking test.

A betaine‐based zwitterionic polymer poly sulfobetaine methacrylate (PSBMA) is employed as interfacial material in p‐i‐n perovskite solar cells. Through improving the interfacial affinity and regulating the energy level at the anode and cathode, respectively, the power conversion efficiency as well as storage stability of the devices greatly improve. In addition, PSBMA also shows advantages in large active area devices.

To improve the performance of perovskite solar cells (Pero‐SCs), a betaine‐based zwitterionic polymer poly(sulfobetaine methacrylate) (denoted by PSBMA) is employed as interlayers at both the anode and cathode in p‐i‐n Pero‐SCs. 1) At the anode side, PSBMA acts as a glue to stitch the two interfacially unfavorable materials: perovskite and poly(bis(4‐phenyl)(2,4,6‐trimethylphenyl)amine), by which the quality of perovskite films as well as the corresponding device performance greatly improve. 2) At the cathode side, PSBMA smoothes the energy levels between PC₆₁BM and Al, and thus facilitates the electron injection efficiency. The power conversion efficiency (PCE) is promoted from 17.31% to 19.16% after PSBMA is introduced as both anode and cathode sides of the p‐i‐n Pero‐SCs. More importantly, PSBMA also shows great potential for large active area (1 cm × 1 cm) Pero‐SCs, and a PCE as high as 15.7% is achieved.

Black phosphorus quantum dots (BPQDs)‐assisted growth of a perovskite film is reported. Serving as heterogeneous nucleation centers, the BPQDs assist in the crystallization of the perovskite film, achieving perovskite films with higher crystallinity and less defects. Consequently, the perovskite solar cells made with BPQDs achieve a maximum power conversion efficiency of 20% and an encouraging improved thermal stability.

Crystallinity and trap‐state density of a perovskite film play a critical role in the performance of corresponding perovskite solar cells (PVSCs). Herein, liquid‐phase‐exfoliated black phosphorus quantum dots (BPQDs) are incorporated into the perovskite precursor solution as additives to direct the formation of the perovskite film, i.e., methylammonium lead iodide (MAPbI₃). It is found that the perovskite films made with BPQDs have higher crystallinity and less nonradiative detects compared with the pristine ones, leading to longer carrier lifetime and higher carrier collection efficiency. Time‐of‐flight secondary‐ion mass spectra and surface density calculation of BPQDs reveal that the improvement of the perovskite film quality may be related to the heterogeneous nucleation of the perovskite film at the BPQDs. PVSCs using MAPbI₃ films made with BPQDs achieve a maximum power conversion efficiency of 20.0% and an encouraging thermal stability of T ₈₀ = 100 h at 100 °C. Both values are remarkably higher than the devices with pristine perovskite films. Therefore, this work demonstrates the potential of the 2D materials quantum dots‐assisted growth method for high‐performance PVSCs.

An oxidized poly(3,4‐ethylenedioxythiphene):poly(styrenesulfonate) (PEDOT:PSS) monolayer is constructed to demonstrate the in‐plane movement of charge carriers in the charge transfer layer, which possibly leads to severe charge recombination at the interfaces. Consequently, a perovskite solar cell fabricated on the oxidized PEDOT:PSS monolayer yields a power conversion efficiency of 18.8% with a high fill factor of 82%.

Charge extraction at the active layer‐electrode interfaces is critical in obtaining highly efficient planar perovskite solar cells (PSCs). It is commonly achieved by enhancing the charge carrier mobility of the charge transfer layer (CTL) that possesses a desirable energy level. Nevertheless, the in‐plane movement of charge carriers in the CTL possibly leads to severe charge recombination in the presence of defects at the interfaces. To verify this overlooked possibility, herein, an oxidized monolayer of poly(3,4‐ethylenedioxythiphene):poly(styrenesulfonate) (PEDOT:PSS) hole transfer layer (HTL) is constructed by water rinsing followed by H₂O₂ oxidation. The oxidized PEDOT:PSS monolayer ensures a high charge transfer ability from perovskite to electrode, but at the same time limits in‐plane charge transport. An inverted planar PSC fabricated on the oxidized PEDOT:PSS monolayer yields a power conversion efficiency (PCE) of 18.8%, higher than 17.0% of the control device based on a pristine PEDOT:PSS monolayer. The main contribution comes from the fill factor (FF), which is as high as 82%. Characterizations indicate that the conjugation length of PEDOT chains is decreased after H₂O₂ oxidation, which lowers the conductivity of PEDOT:PSS HTL in the in‐plane direction. This study suggests that the charge recombination at the electrode interfaces due to in‐plane charge transport in the CTLs is not to be neglected.

Roll‐to‐roll processed perovskite solar cells are fabricated using slot‐die coating by the hot deposition method. The hot deposition approach is scalable and can be performed in an uncontrolled ambient environment without additional processes. A polymer additive, polyethylene oxide, is introduced to improve the processability and proves useful for improving tolerance to humidity, resulting in improved reliability for industrial manufacturing.

Abstract

Heating‐assisted deposition is an industry‐friendly scalable deposition method. This manufacturing method is employed together with slot die coating to fabricate perovskite solar cells via a roll‐to‐roll process. The feasibility of the method is demonstrated after initial testing on a rigid substrate using a benchtop slot die coater in air. The fabricated solar cells exhibit power conversion efficiencies (PCEs) up to 14.7%. A nonelectroactive polymer additive is used with the perovskite formulation and found to improve its humidity tolerance significantly. These deposition parameters are also used in the roll‐to‐roll setup. The perovskite layer and other solution‐processed layers are slot die‐coated, and the fabricated device shows PCEs up to 11.7%, which is the highest efficiency obtained from a fully roll‐to‐roll processed perovskite solar cell to date.

CsPbBr₃ perovskite nanowires are incorporated into a bulk halide perovskite thin film based on solution processing. This method leads to a very uniform film surface region with optimized compositions and electronic structures, thereby enabling highly efficient and stable perovskite solar cells. This study points to a new direction of research in harnessing the interplay between perovskite nanocrystals and thin films.

Abstract

Perovskite solar cells (PSCs) have recently experienced a rapid rise in power conversion efficiency (PCE), but the prevailing PSCs with conventional mesoscopic or planar device architectures still contain nonideal perovskite/hole‐transporting‐layer (HTL) interfaces, limiting further enhancement in PCE and device stability. In this work, CsPbBr₃ perovskite nanowires are employed for modifying the surface electronic states of bulk perovskite thin films, forming compositionally‐graded heterojunction at the perovskite/HTL interface of PSCs. The nanowire morphology is found to be key to achieving lateral homogeneity in the perovskite film surface states resulting in a near‐ideal graded heterojunction. The hidden role of such lateral homogeneity on the performance of graded‐heterojunction PSCs is revealed for the first time. The resulting PSCs show high PCE up to 21.4%, as well as high operational stability, which is superior to control PSCs fabricated without CsPbBr₃‐nanocrystals modification and with CsPbBr₃‐nanocubes modification. This study demonstrates the promise of controlled hybridization of perovskite nanowires and bulk thin films for more efficient and stable PSCs.

Solution‐phase van der Waals epitaxy growth of MAPbI₃ perovskite films on MoS₂ flakes is observed. The in‐plane coupling between the perovskite and the MoS₂ crystal lattices leads to perovskite films with larger grain size, lower trap density, and preferential growth orientation. Consequently, the efficiency of fabricated perovskite solar cells is substantially improved by the MoS₂ flakes as interfacial layers.

Abstract

The quality of perovskite films is critical to the performance of perovskite solar cells. However, it is challenging to control the crystallinity and orientation of solution‐processed perovskite films. Here, solution‐phase van der Waals epitaxy growth of MAPbI₃ perovskite films on MoS₂ flakes is reported. Under transmission electron microscopy, in‐plane coupling between the perovskite and the MoS₂ crystal lattices is observed, leading to perovskite films with larger grain size, lower trap density, and preferential growth orientation along (110) normal to the MoS₂ surface. In perovskite solar cells, when perovskite active layers are grown on MoS₂ flakes coated on hole‐transport layers, the power conversion efficiency is substantially enhanced for 15%, relatively, due to the increased crystallinity of the perovskite layer and the improved hole extraction and transfer rate at the interface. This work paves a way for preparing high‐performance perovskite solar cells and other optoelectronic devices by introducing 2D materials as interfacial layers.

The crystallization pathways of mixed perovskites under spin‐coating are investigated via in situ grazing‐incidence wide‐angle X‐ray scattering (GIWAXS), which reveals the existence of an “annealing window”. The as‐cast film should be timely annealed within the annealing window to achieve a high‐quality perovskite film. The incorporation of Cs⁺ can remarkably extend the annealing window, thereby improving the device performance and reproducibility.

Abstract

Mixed perovskites have achieved substantial successes in boosting solar cell efficiency, but the complicated perovskite crystal formation pathway remains mysterious. Here, the detailed crystallization process of mixed perovskites (FA_0.83MA_0.17Pb(I_0.83Br_0.17)₃) during spin‐coating is revealed by in situ grazing‐incidence wide‐angle X‐ray scattering measurements, and three phase‐formation stages are identified: I) precursor solution; II) hexagonal δ‐phase (2H); and III) complex phases including hexagonal polytypes (4H, 6H), MAI–PbI₂–DMSO intermediate phases, and perovskite α‐phase. The correlated device performance and ex situ characterizations suggest the existence of an “annealing window” covering the duration of stage II. The spin‐coated film should be annealed within the annealing window to avoid the formation of hexagonal polytypes during the perovskite crystallization process, thus achieving a good device performance. Remarkably, the crystallization pathway can be manipulated by incorporating Cs⁺ ions in mixed perovskites. Combined with density functional theory calculations, the perovskite system with sufficient Cs⁺ will bypass the formation of secondary phases in stage III by promoting the formation of α‐phase both kinetically and thermodynamically, thereby significantly extending the annealing window. This study provides underlying reasons of the time sensitivity of fabricating mixed‐perovskite devices and insightful guidelines for manipulating the perovskite crystallization pathways toward higher performance.

Publication date: July 2019

Source: Nano Energy, Volume 61

Author(s): Zhi Fang, Minghui Shang, Xinmei Hou, Yapeng Zheng, Zhentao Du, Zuobao Yang, Kuo-Chih Chou, Weiyou Yang, Zhong Lin Wang, Ya Yang

Graphical abstract

We reported the advance on bandgap alignment of α-CsPbI₃ perovskites (PVSKs) through B-site minor doping engineering with synergistically enhanced stability and optical property, which was predicted by density functional theory calculation. The present work establishes the rule that the bandgaps of α-CsPbI₃ PVSKs decrease with the sequential change of dopants from Ge, to Sn and then to Si at a fixed doping level, and reduce with the raise of doping concentrations for a given dopant, suggesting the bandgap engineering of PVSKs via B-site minor doping strategy. Furthermore, it is discovered that minor doping of Sn²⁺ with an optimal concentration 2.8 at.% could not only bring a suitable tolerance factor for CsPbI₃ PVSKs with a slighter lattice distortion, but also increase the charge density of Pb²⁺ to enhance the interaction between Pb²⁺ and I⁻, which consequently improve their global stability. Current work might direct and advance the exploration of novel PVSKs with totally improved performance, which could inspire their future applications in efficient solar cell.

A rutile TiO₂ electron transport layer (ETL) was prepared. The thickness and crystallinity can be controlled by deposition time and sintering temperature. Rutile TiO₂ has higher conductivity than anatase for faster electron transfer, better interface contact with the perovskite layer, and a lower trap density. These facilitate the charge extraction and collection and reducing carrier recombination.

Abstract

Interfacial charge collection efficiency has demonstrated significant effects on the power conversion efficiency (PCE) of perovskite solar cells (PSCs). Herein, crystalline phase‐dependent charge collection is investigated by using rutile and anatase TiO₂ electron transport layer (ETL) to fabricate PSCs. The results show that rutile TiO₂ ETL enhances the extraction and transportation of electrons to FTO and reduces the recombination, thanks to its better conductivity and improved interface with the CH₃NH₃PbI₃ (MAPbI₃) layer. Moreover, this may be also attributed to the fact that rutile TiO₂ has better match with perovskite grains, and less trap density. As a result, comparing with anatase TiO₂ ETL, MAPbI₃ PSCs with rutile TiO₂ ETL delivers significantly enhanced performance with a champion PCE of 20.9 % and a large open circuit voltage (V _OC) of 1.17 V.

Pb(SCN)₂ functions at the grain boundaries and pinholes to in situ polish the perovskite film surface. A 425 nm‐thick CsPbI₂Br film with high crystalline, smooth, and uniform surface morphology is obtained, with an efficiency of 10.44% for a low cost and stable carbon‐based perovskite solar cell processed under low‐temperature (150 °C).

Improvement in stability and an economical processing technique are the main aspects of the commercialization of perovskite solar cells (PSCs). In this study, a 425 nm‐thick CsPbI₂Br film with a high crystalline, smooth, and uniform surface morphology is obtained by Pb(SCN)₂ passivating the grain boundaries under low temperature (150 °C). The results of a series of electrochemical analyses, including space‐charge‐limited‐current (SCLC), open‐circuit voltage decay (OCVD), electrical impedance spectroscopy (EIS), intensity‐modulated photocurrent spectroscopy (IMPS), and intensity‐modulated photovoltage spectroscopy (IMVS), demonstrate that the trap density of the CsPbI₂Br film is greatly reduced with Pb(SCN)₂, which effectively inhibits the interface recombination and promotes charge transport in CsPbI₂Br PSC. Efficiencies of 12.22% and 10.44% are achieved for low‐temperature‐processed CsPbI₂Br planar‐architecture PSCs with ITO/SnO₂/CsPbI₂Br/ poly(3‐hexylthiophene) (P3HT)/Ag and ITO/SnO₂/CsPbI₂Br/carbon, respectively. This low‐cost, high‐efficiency carbon‐based inorganic PSC shows potential industrial application, especially for tandem solar cells.

The optical, morphological, and photovoltaic changes as a result of the halide exchange process at the solid‐state phase of perovskite‐based solar cells are studied.

The optical properties of halide perovskite are already tuned in the initial solution by choosing the preferred precursors. However, it is not obvious that the optical properties change following perovskite crystallization; moreover, the mechanism in this case is not clear. Herein, it is shown that the optical properties are not necessarily “fixed” following perovskite crystallization. The phenomenon using the halide exchange process in the solid phase of an already crystalized perovskite is demonstrated. The effects of formamidinium iodide (FAI) and formamidinium bromide (FABr) are investigated post‐treatment on the physical, optical, and PV properties of Cs_0.2FA_0.8Pb(I_0.75Br_0.25)₃ perovskite. Various FAI/FABr ratios in the post‐treatment solutions show that a halide exchange occurs in the solid‐state phase following the crystallization of the perovskite film. Energy‐dispersive spectroscopy line scan made on focused ion beam samples show that the bromide is present deep inside the film post‐treatment, which supports the fact that the reaction is not occurring only on the surface. Charge extraction and voltage decay measurements of the complete solar cells support the structural changes due to the halide exchange. This work enhances the knowledge of halide exchange in already crystalized perovskite.

A liquid crystal (LC) molecule (4′‐heptyl‐4‐biphenylcarbonitrile) is first used as a “binding agent” to connect grain boundaries of perovskite. The crystal orientation of perovskite grains is controlled and the electron transport process is accelerated after treating with LC; these are reflected by the significant improvement in power conversion efficiency and high fill factor. Remarkably, the LC greatly contributes to the humid‐stability of perovskite solar cells.

Hybrid perovskites have rapidly emerged as highly promising optoelectronic materials for perovskite solar cells (PSCs), whereas solution‐processed perovskite films usually contain a large amount of grain‐boundary network, which is unbeneficial for efficient film function, including charge transport and environmental stability. Herein, a liquid crystal (LC) molecule is first used as a “binding agent” to connect grains and fill grain boundaries of perovskite. The LC molecule (4′‐heptyl‐4‐biphenylcarbonitrile) interacts with PbI₂ to control the crystal orientation for fine and oriented perovskite grains, which accelerates electron transport and enhances environmental stability. Consequently, compared with the pristine devices, the power conversion efficiency of the LC‐based device increases from 17.14% to 20.19% with a high fill factor (over 80%). Remarkably, the LC‐based PSCs retain 92% of their initial efficiency at 25 °C, and a relative humidity of 70% after 500 h, whereas the control samples are almost degraded completely under the same conditions.