3D–2D–0D Interface Profiling for Record Efficiency All‐Inorganic CsPbBrI2 Perovskite Solar Cells with Superior Stability

All‐inorganic CsPbBrI₂ perovskite has great advantages in terms of ambient phase stability and suitable band gap (1.91 eV) for photovoltaic applications. However, the typically used structure causes reduced device performance, primarily due to the large recombination at the interface between the perovskite, and the hole‐extraction layer (HEL). In this paper, an efficient CsPbBrI₂ perovskite solar cell (PSC) with a dimensionally graded heterojunction is reported, in which the CsPbBrI₂ material is distributed within bulk–nanosheet–quantum dots or 3D–2D–0D dimension‐profiled interface structure so that the energy alignment is optimized in between the valence and conduction bands of both CsPbBrI₂ and the HEL layers. Specifically, the valence‐/conduction‐band edge is leveraged to bend with synergistic advantages: the graded combination enhances the hole extraction and conduction efficiency with effectively decreased recombination loss during the hole‐transfer process, leading to an enhanced built‐in electric field, hence a high V_OC of as much as 1.19 V. The profiled structure induces continuously upshifted energy levels, resulting in a higher J_SC of as much as 12.93 mA cm^?2 and fill factor as high as 80.5%, and therefore record power conversion efficiency (PCE) of 12.39%. As far as it is known, this is the highest PCE for CsPbBrI₂ perovskite‐based PSC.     

High‐Performance Perovskite Solar Cells with Enhanced Environmental Stability Based on a (p‐FC6H4C2H4NH3)2[PbI4] Capping Layer

Supported by the density functional theory (DFT) calculations, for the first time, a fluorinated aromatic cation, 2‐(4‐fluorophenyl)ethyl ammonium iodide (FPEAI), is introduced to grow in situ a low dimensional perovskite layer atop 3D perovskite film with excess PbI₂. The resulted (p‐FC₆H₄C₂H₄NH₃)₂[PbI₄] perovskite functions as a protective capping layer to protect the 3D perovskite from moisture. In the meantime, the thin layer facilitates charge transfer at the interfaces, thereby reducing the nonradiative recombination pathways. Laser scanning confocal microscopy unveils visually the distribution of the 2D perovskite layer on top of the 3D perovskite. When employing the 3D–2D perovskite as the absorbing layer in the photovoltaic cells, a high power conversion efficiency of 20.54% is realized. Superior device performance and moisture stability are observed with the modified perovskite over the whole stability test period.     

Efficient Perovskite Photovoltaic‐Thermoelectric Hybrid Device

An efficient perovskite photovoltaic‐thermoelectric hybrid device is demonstrated by integrating the hole‐conductor‐free perovskite solar cell based on TiO₂/ZrO₂/carbon structure and the thermoelectric generator. The whole solar spectrum of AM 1.5 G is fully utilized with the ≈1.55 eV band gap perovskite (5‐AVA)_x(MA)_1?xPbI₃ absorbing the visible light and the carbon back contact absorbing the infrared light. The added thermoelectric generator improves the device performance by converting the thermal energy into electricity via the Seebeck effect. An optimized hybrid device is obtained with a maximum point power output of 20.3% and open‐circuit voltage of 1.29 V under the irradiation of 100 mW cm^?2.     

Interface Engineering for Highly Efficient and Stable Planar p‐i‐n Perovskite Solar Cells

Organic‐inorganic halide perovskite materials have become a shining star in the photovoltaic field due to their unique properties, such as high absorption coefficient, optimal bandgap, and high defect tolerance, which also lead to the breathtaking increase in power conversion efficiency from 3.8% to over 22% in just seven years. Although the highest efficiency was obtained from the TiO₂ mesoporous structure, there are increasing studies focusing on the planar structure device due to its processibility for large‐scale production. In particular, the planar p‐i‐n structure has attracted increasing attention on account of its tremendous advantages in, among other things, eliminating hysteresis alongside a competitive certified efficiency of over 20%. Crucial for the device performance enhancement has been the interface engineering for the past few years, especially for such planar p‐i‐n devices. The interface engineering aims to optimize device properties, such as charge transfer, defect passivation, band alignment, etc. Herein, recent progress on the interface engineering of planar p‐i‐n structure devices is reviewed. This review is mainly focused on the interface design between each layer in p‐i‐n structure devices, as well as grain boundaries, which are the interfaces between polycrystalline perovskite domains. Promising research directions are also suggested for further improvements.     

Hybrid Perovskite‐Organic Flexible Tandem Solar Cell Enabling Highly Efficient Electrocatalysis Overall Water Splitting

Perovskite‐organic tandem solar cells are attracting more attention due to their potential for highly efficient and flexible photovoltaic device. In this work, efficient perovskite‐organic monolithic tandem solar cells integrating the wide bandgap perovskite (1.74 eV) and low bandgap organic active PBDB‐T:SN6IC‐4F (1.30 eV) layer, which serve as the top and bottom subcell, respectively, are developed. The resulting perovskite‐organic tandem solar cells with passivated wide‐bandgap perovskite show a remarkable power conversion efficiency (PCE) of 15.13%, with an open‐circuit voltage (V_oc) of 1.85 V, a short‐circuit photocurrent (J_sc) of 11.52 mA cm^?2, and a fill factor (FF) of 70.98%. Thanks to the advantages of low temperature fabrication processes and the flexibility properties of the device, a flexible tandem solar cell which obtain a PCE of 13.61%, with V_oc of 1.80 V, J_sc of 11.07 mA cm^?2, and FF of 68.31% is fabricated. Moreover, to demonstrate the achieved high V_oc in the tandem solar cells for potential applications, a photovoltaic (PV)‐driven electrolysis system combing the tandem solar cell and water splitting electrocatalysis is assembled. The integrated device demonstrates a solar‐to‐hydrogen efficiency of 12.30% and 11.21% for rigid, and flexible perovskite‐organic tandem solar cell based PV‐driven electrolysis systems, respectively.     

Low‐Temperature Solution‐Processed CuCrO2 Hole‐Transporting Layer for Efficient and Photostable Perovskite Solar Cells

Organic–inorganic hybrid perovskite solar cells (PVSCs) have become the front‐running photovoltaic technology nowadays and are expected to profoundly impact society in the near future. However, their practical applications are currently hampered by the challenges of realizing high performance and long‐term stability simultaneously. Herein, the development of inverted PVSCs is reported based on low temperature solution‐processed CuCrO₂ nanocrystals as a hole‐transporting layer (HTL), to replace the extensively studied NiO_x counterpart due to its suitable electronic structure and charge carrier transporting properties. A ≈45 nm thick compact CuCrO₂ layer is incorporated into an inverted planar configuration of indium tin oxides (ITO)/c‐CuCrO₂/perovskite/[6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM)/bathocuproine (BCP)/Ag, to result in the high steady‐state power conversion efficiency of 19.0% versus 17.1% for the typical low temperature solution‐processed NiO_x‐based devices. More importantly, the optimized CuCrO₂‐based device exhibits a much enhanced photostability than the reference device due to the greater UV light‐harvesting of the CuCrO₂ layer, which can efficiently prevent the perovskite film from intense UV light exposure to avoid associated degradation. The results demonstrate the promising potential of CuCrO₂ nanocrystals as an efficient HTL for realizing high‐performance and photostable inverted PVSCs.     

Spontaneously Self‐Assembly of a 2D/3D Heterostructure Enhances the Efficiency and Stability in Printed Perovskite Solar Cells

As perovskite solar cells (PSCs) are highly efficient, demonstration of high‐performance printed devices becomes important. 2D/3D heterostructures have recently emerged as an attractive way to relieving the film inhomogeneity and instability in perovskite devices. In this work, a 2D/3D ensemble with 2D perovskites self‐assembled atop 3D methylammonium lead triiodide (MAPbI₃) via a one‐step printing process is shown. A clean and flat interface is observed in the 2D/3D bilayer heterostructure for the first time. The 2D perovskite capping layer significantly suppresses nonradiative charge recombination, resulting in a marked increase in open‐circuit voltage (V_OC) of the devices by up to 100 mV. An ultrahigh V_OC of 1.20 V is achieved for MAPbI₃ PSCs, corresponding to 91% of the Shockley–Queisser limit. Moreover, notable enhancement in light, thermal, and moisture stability is obtained as a result of the protective barrier of the 2D perovskites. These results suggest a viable approach for scalable fabrication of highly efficient perovskite solar cells with enhanced environmental stability.     

Thermodynamic Efficiency Limit of Molecular Donor‐Acceptor Solar Cells and its Application to Diindenoperylene/C60‐Based Planar Heterojunction Devices

In organic photovoltaic (PV) cells, the well‐established donor‐acceptor (D/A) concept enabling photo‐induced charge transfer between two partners with suitable energy level alignment has proven extremely successful. Nevertheless, the introduction of such a heterojunction is accompanied with additional energy losses as compared to an inorganic homojunction cell, owing to the presence of a charge‐transfer (CT) state at the D/A interface. Based on the principle of detailed balance, a modified Shockley‐Queisser theory is developed including the essential effects of interfacial CT states, that allows for a quantitative assessment of the thermodynamic efficiency limits of molecular D/A solar cells. Key parameters, apart from the optical gap of the absorber material, entering the model are the energy (E_CT) and relative absorption strength (α_CT) of the CT state. It is demonstrated how the open‐circuit voltage (V_OC) and thus the power conversion efficiency are affected by different parameter values. Furthermore, it is shown that temperature dependent device characteristics can serve to determine the CT energy, and thus the upper limit of V_OC for a given D/A combination, as well as to quantify non‐radiative recombination losses. The model is applied to diindenoperylene (DIP)‐based photovoltaic devices, with open‐circuit voltages between 0.9 and 1.4 V, depending on the partner, that have recently been reported.     

Simultaneous Improvement of Photovoltaic Performance and Stability by In Situ Formation of 2D Perovskite at (FAPbI3)0.88(CsPbBr3)0.12/CuSCN Interface

To solve the stability issues of perovskite solar cells (PSC), here a novel interface engineering strategy that a versatile ultrathin 2D perovskite (5‐AVA)₂PbI₄ (5‐AVA = 5‐ammoniumvaleric acid) passivation layer that is in situ incorporated at the interface between (FAPbI₃)_0.88(CsPbBr₃)_0.12 and the hole transporting CuSCN is reported. Surface analysis using X‐ray photoelectron spectroscopy confirms the formation of 2D perovskite. Hysteresis is reduced by the interfacial 2D layer, which could be ascribed to improvement of interfacial charge extraction efficiency, associated with suppression of recombination. Moreover, introduction of the interface passivating layer enhances the moisture stability and photostability as compared to the control perovskite film due to hydrophobic nature of 2D perovskite. The unencapsulated device retains 98% of the initial power conversion efficiency (PCE) after 63 d under moisture exposure of about 10% in the dark. A PCE of the control device is boosted from 13.72 to 16.75% as a consequence of enhanced open‐circuit voltage (V_oc) and fill factor along with slightly increased short‐circuit current density (J_sc), which results from reduced trap states of (FAPbI₃)_0.88(CsPbBr₃)_0.12 as evidenced by enhanced carrier lifetimes and charge extraction. The perovskite/hole transport material interface engineering gives insight into simultaneous improvements of PCE and device stability.     

Surface Engineering of TiO2 ETL for Highly Efficient and Hysteresis‐Less Planar Perovskite Solar Cell (21.4%) with Enhanced Open‐Circuit Voltage and Stability

Interfacial studies and band alignment engineering on the electron transport layer (ETL) play a key role for fabrication of high‐performance perovskite solar cells (PSCs). Here, an amorphous layer of SnO₂ (a‐SnO₂) between the TiO₂ ETL and the perovskite absorber is inserted and the charge transport properties of the device are studied. The double‐layer structure of TiO₂ compact layer (c‐TiO₂) and a‐SnO₂ ETL leads to modification of interface energetics, resulting in improved charge collection and decreased carrier recombination in PSCs. The optimized device based on a‐SnO₂/c‐TiO₂ ETL shows a maximum power conversion efficiency (PCE) of 21.4% as compared to 19.33% for c‐TiO₂ based device. Moreover, the modified device demonstrates a maximum open‐circuit voltage (V_oc) of 1.223 V with 387 mV loss in potential, which is among the highest reported value for PSCs with negligible hysteresis. The stability results show that the device on c‐TiO₂/a‐SnO₂ retains about 91% of its initial PCE value after 500 h light illumination, which is higher than pure c‐TiO₂ (67%) based devices. Interestingly, using a‐SnO₂/c‐TiO₂ ETL the PCE loss was only 10% of initial value under continuous UV light illumination after 30 h, which is higher than that of c‐TiO₂ based device (28% PCE loss).     

Coordination Engineering of Single‐Crystal Precursor for Phase Control in Ruddlesden–Popper Perovskite Solar Cells

2D Ruddlesden–Popper perovskites (RPPs) have recently drawn significant attention because of their structural variability that can be used to tailor optoelectronic properties and improve the stability of derived photovoltaic devices. However, charge separation and transport in 2D perovskite solar cells (PSCs) suffer from quantum well barriers formed during the processing of perovskites. It is extremely difficult to manage phase distributions in 2D perovskites made from the stoichiometric mixtures of precursor solutions. Herein, a generally applicable guideline is demonstrated for precisely controlling phase purity and arrangement in RPP films. By visually presenting the critical colloidal formation of the single‐crystal precursor solution, coordination engineering is conducted with a rationally selected cosolvent to tune the colloidal properties. In nonpolar cosolvent media, the derived colloidal template enables RPP crystals to preferentially grow along the vertically ordered alignment with a narrow phase variation around a target value, resulting in efficient charge transport and extraction. As a result, a record‐high power conversion efficiency (PCE) of 14.68% is demonstrated for a (TEA)₂(MA)₂Pb₃I₁₀ (n = 3) photovoltaic device with negligible hysteresis. Remarkably, superior stability is achieved with 93% retainment of the initial efficiency after 500 h of unencapsulated operation in ambient air conditions.     

2‐Thiopheneformamidinium‐Based 2D Ruddlesden–Popper Perovskite Solar Cells with Efficiency of 16.72% and Negligible Hysteresis

Formamidinium (FA)‐based 3D perovskite solar cells (PSCs) have been widely studied and they show reduced bandgap, enhanced stability, and improved efficiency compared to MAPbI₃‐based devices. Nevertheless, the FA‐based spacers have rarely been studied for 2D Ruddlesden–Popper (RP) perovskites, which have drawn wide attention due to their enormous potential for fabricating efficient and stable photovoltaic devices. Here, for the first time, FA‐based derivative, 2‐thiopheneformamidinium (ThFA), is successfully synthesized and employed as an organic spacer for 2D RP PSCs. A precursor organic salts‐assisted crystal growth technique is further developed to prepare high quality 2D (ThFA)₂(MA)_n?1Pb_nI_3n+1 (nominal n = 3) perovskite films, which shows preferential vertical growth orientations, high charge carrier mobilities, and reduced trap density. As a result, the 2D RP PSCs with an inverted planar p‐i‐n structure exhibit a dramatically improved power conversion efficiency (PCE) from 7.23% to 16.72% with negligible hysteresis, which is among the highest PCE in 2D RP PSCs with low nominal n‐value of 3. Importantly, the optimized 2D PSCs exhibit a dramatically improved stability with less than 1% degradation after storage in N₂ for 3000 h without encapsulation. These findings provide an effective strategy for developing FA‐based organic spacers toward highly efficient and stable 2D PSCs.     

Benzylamine‐Treated Wide‐Bandgap Perovskite with High Thermal‐Photostability and Photovoltaic Performance

Mixed iodide‐bromide organolead perovskites with a bandgap of 1.70–1.80 eV have great potential to boost the efficiency of current silicon solar cells by forming a perovskite‐silicon tandem structure. Yet, the stability of the perovskites under various application conditions, and in particular combined light and heat stress, is not well studied. Here, FA_0.15Cs_0.85Pb(I_0.73Br_0.27)₃, with an optical bandgap of ≈1.72 eV, is used as a model system to investigate the thermal‐photostability of wide‐bandgap mixed halide perovskites. It is found that the concerted effect of heat and light can induce both phase segregation and decomposition in a pristine perovskite film. On the other hand, through a postdeposition film treatment with benzylamine (BA) molecules, the highly defective regions (e.g., film surface and grain boundaries) of the film can be well passivated, thus preventing the progression of decomposition or phase segregation in the film. Besides the stability improvement, the BA‐modified perovskite solar cells also exhibit excellent photovoltaic performance, with the champion device reaching a power conversion efficiency of 18.1%, a stabilized power output efficiency of 17.1% and an open‐circuit voltage (V _oc) of 1.24 V.     

Supramolecular Engineering for Formamidinium‐Based Layered 2D Perovskite Solar Cells: Structural Complexity and Dynamics Revealed by Solid‐State NMR Spectroscopy

Perovskite solar cells are one of the most promising photovoltaic technologies, although their molecular level design and stability toward environmental factors remain a challenge. Layered 2D Ruddlesden–Popper perovskite phases feature an organic spacer bilayer that enhances their environmental stability. Here, the concept of supramolecular engineering of 2D perovskite materials is demonstrated in the case of formamidinium (FA) containing A₂FA_n?1Pb_nI_3n+1 formulations by employing (adamantan‐1‐yl)methanammonium (A) spacers exhibiting propensity for strong Van der Waals interactions complemented by structural adaptability. The molecular design translates into desirable structural features and phases with different compositions and dimensionalities, identified uniquely at the atomic level by solid‐state NMR spectroscopy. For A₂FA₂Pb₃I₁₀, efficiencies exceeding 7% in mesoscopic device architectures without any additional treatment or use of antisolvents for ambient temperature film deposition are achieved. This performance improvement over the state‐of‐the‐art FA‐based 2D perovskites is accompanied by high operational stability under humid ambient conditions, which illustrates the utility of the approach in perovskite solar cells and sets the basis for advanced supramolecular design in the future.     

Electron‐Beam‐Evaporated Nickel Oxide Hole Transport Layers for Perovskite‐Based Photovoltaics

High‐quality charge carrier transport materials are of key importance for stable and efficient perovskite‐based photovoltaics. This work reports on electron‐beam‐evaporated nickel oxide (NiO_x) layers, resulting in stable power conversion efficiencies (PCEs) of up to 18.5% when integrated into solar cells employing inkjet‐printed perovskite absorbers. By adding oxygen as a process gas and optimizing the layer thickness, transparent and efficient NiO_x hole transport layers (HTLs) are fabricated, exhibiting an average absorptance of only 1%. The versatility of the material is demonstrated for different absorber compositions and deposition techniques. As another highlight of this work, all‐evaporated perovskite solar cells employing an inorganic NiO_x HTL are presented, achieving stable PCEs of up to 15.4%. Along with good PCEs, devices with electron‐beam‐evaporated NiO_x show improved stability under realistic operating conditions with negligible degradation after 40 h of maximum power point tracking at 75 °C. Additionally, a strong improvement in device stability under ultraviolet radiation is found if compared to conventional perovskite solar cell architectures employing other metal oxide charge transport layers (e.g., titanium dioxide). Finally, an all‐evaporated perovskite solar mini‐module with a NiO_x HTL is presented, reaching a PCE of 12.4% on an active device area of 2.3 cm².     

SrTiO3/Al2O3‐Graphene Electron Transport Layer for Highly Stable and Efficient Composites‐Based Perovskite Solar Cells with 20.6% Efficiency

For practical use of perovskite solar cells (PSCs) the instability issues of devices, attributed to degradation of perovskite molecules by moisture, ions migration, and thermal‐ and light‐instability, have to be solved. Herein, highly efficient and stable PSCs based on perovskite/Ag‐reduced graphene oxide (Ag‐rGO) and mesoporous Al₂O₃/graphene (mp‐AG) composites are reported. The mp‐AG composite is conductive with one‐order of magnitude higher mobility than mp‐TiO₂ and used for electron transport layer (ETL). Compared to the mp‐TiO₂ ETL based cells, the champion device based on perovskite/Ag‐rGO and SrTiO₃/mp‐AG composites shows overall a best performance (i.e., V_OC = 1.057 V, J_SC = 25.75 mA cm^?2, fill factor (FF) = 75.63%, and power conversion efficiency (PCE) = 20.58%). More importantly, the champion device without encapsulation exhibits not only remarkable thermal‐ and photostability but also long‐term stability, retaining 97–99% of the initial values of photovoltaic parameters and sustaining ≈93% of initial PCE over 300 d under ambient conditions.     

Outstanding Performance of Hole‐Blocking Layer‐Free Perovskite Solar Cell Using Hierarchically Porous Fluorine‐Doped Tin Oxide Substrate

Perovskite solar cells (PSCs) are of great interest in current photovoltaic research due to their extraordinary power conversion efficiency of ≈20% and boundless potentialities. The high efficiency has been mostly obtained from TiO₂‐based PSCs, where TiO₂ is utilized as a hole‐blocking, mesoporous layer. However, trapped charges and the light‐induced photocatalytic effect of TiO₂ seriously degrade the perovskite and preclude PSCs from being immediately commercialized. Herein, a simplified PSC is successfully fabricated by eliminating the problematic TiO₂ layers, using instead a fluorine‐doped tin oxide (FTO)/perovskite/hole–conductor/Au design. Simultaneously, the sluggish charge extraction at the FTO/perovskite interface is overcome by modifying the surface of the FTO to a porous structure using electrochemical etching. This surface engineering enables a substantial increase in the photocurrent density and mitigation of the hysteretic behavior of the pristine FTO‐based PSC; a remarkable 19.22% efficiency with a low level of hysteresis is obtained. This performance is closely approaching that of conventional PSCs and may facilitate their commercialization due to improved convenience, lower cost, greater stability, and potentially more efficient mass production.     

Fusing Nanowires into Thin Films: Fabrication of Graded‐Heterojunction Perovskite Solar Cells with Enhanced Performance

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.     

Aerosol‐Jet‐Assisted Thin‐Film Growth of CH3NH3PbI3 Perovskites—A Means to Achieve High Quality,Defect‐Free Films for Efficient Solar Cells

A high level of automation is desirable to facilitate the lab‐to‐fab process transfer of the emerging perovskite‐based solar technology. Here, an automated aerosol‐jet printing technique is introduced for precisely controlling the thin‐film perovskite growth in a planar heterojunction p–i–n solar cell device structure. The roles of some of the user defined parameters from a computer‐aided design file are studied for the reproducible fabrication of pure CH₃NH₃PbI₃ thin films under near ambient conditions. Preliminary power conversion efficiencies up to 15.4% are achieved when such films are incorporated in a poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate‐perovskite‐phenyl‐C71‐butyric acid methyl ester type device format. It is further shown that the deposition of atomized materials in the form of a gaseous mist helps to form a highly uniform and PbI₂ residue‐free CH₃NH₃PbI₃ film and offers advantages over the conventional two‐step solution approach by avoiding the detrimental solid–liquid interface induced perovskite crystallization. Ultimately, by integrating full 3D motion control, the fabrication of perovskite layers directly on a 3D curved surface becomes possible. This work suggests that 3D automation with aerosol‐jet printing, once fully optimized, could form a universal platform for the lab‐to‐fab process transfer of solution‐based perovskite photovoltaics and steer development of new design strategies for numerous embedded structural power applications.     

Effect of Photogenerated Dipoles in the Hole Transport Layer on Photovoltaic Performance of Organic–Inorganic Perovskite Solar Cells

Judicious choice of transport layer in organic–inorganic halide perovskite solar cells can be one of the essential parameters in photovoltaic design and fabrication techniques. This article reports the effect of optically generated dipoles in transport layer on the photovoltaic actions in active layer in perovskite solar cells with the architecture of indium tin oxide (ITO)/TiO _x /CH₃NH₃PbI_3–x Cl _x /hole transport layer (HTL)/Au. Here, PTB7‐thieno[3,4‐b]thiophene‐alt‐benzodithiophene and P3HT‐poly(3‐hexylthiophene) are separately used as the HTL with significant and negligible photoinduced dipoles, respectively. Electric field‐induced photoluminescence quenching provides the first‐hand evidence to indicate that the photoinduced dipoles are partially aligned in the amorphous PTB7 layer under the influence of device built‐in field. By monitoring the recombination process through magneto‐photocurrent measurements under device operation condition, it is shown that the photoinduced dipoles in PTB7 layer can decrease the recombination of photogenerated carriers in the active layer in perovskite solar cells. Furthermore, the capacitance measurements suggest that the photoinduced dipoles in PTB7 can decrease charge accumulation at the electrode interface. Therefore, the studies indicate the important role of photoinduced dipoles in the HTL on charge recombination dynamics and provide a fundamental insight on how the polarization in transport layer can influence the device performance in perovskite solar cells.