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[Display omitted] • Bilateral passivation strategy by PEACl doping and NPB post-treatment is proposed. • Construction of GHJ provides a favorable transport pathway for hole migration. • Achieving a PCE of 21.88% for PEACl-SnO 2 -NPB based PSCs with negligible hysteresis. • Improved moisture and thermal stability of PSCs by using synchronous regulation. Defects and inferior charge transport dynamics within devices are key issues that inhibit the improvements of photovoltaic performance and stability. Developing facile and feasible strategies for synchronous passivation of defects regarding charge transport layers (CTLs), perovskite films and their interfaces, and precise tuning of energy level structure, is a definite way to solve above problems. Herein, we develop a synergistic passivation strategy for perovskite films and bilateral interfaces to improve device performance. Firstly, an appropriate amount of phenylethylammonium chloride is adopted to modify SnO 2 electron transport layer (ETL). The complexation reaction between N atoms in –NH 2 and Sn4+ improve the agglomeration of SnO 2 nanoparticles and film quality of SnO 2 ETL. The presence of Cl− ions not only effectively fill oxygen vacancies within SnO 2 ETL, but also participate in regulating crystal growth dynamics of perovskite films, thus improving electron transport properties at interface. Subsequently, p-type conducting material N,N'-Bis-(1-naphthalenyl)-N,N'-bis-phenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) is introduced into anti-solvent chlorobenzene during the preparation of perovskite films to further regulate the crystal quality and achieve full-range defect passivation. Particularly, the introduction of NPB helps to construct a gradient heterojunction between upper perovskite film and SpiroOMeTAD hole transport layer, thus reducing the accumulation of hole carriers near interface and further suppressing current–voltage hysteresis behavior of devices. Additionally, the hydrophobicity of NPB and full range of defect passivation greatly enhance the humidity and thermal stability of devices. Finally, a high power conversion efficiency of 21.88% is obtained with suppressed hysteresis and enhanced long-term stability. This work highlights the role of full-range defect passivation on CTLs, perovskite absorption layers and interfacial charge transport properties, which provide a novel concept for constructing high-performance and stable perovskite devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Iodine ligand-coupled PbS QDs film was firstly used to modify ZnO ETLs to boost photovoltaic performance of PSCs. • Introducing PbS-TBAI layer improves crystal quality of perovskite and forms cascade energy band structure. • A maximum PCE of 20.53 % has been achieved in the PSCs based on ZnO/PbS-TBAI-80 ETLs. Zinc oxide (ZnO) was traditional cathode material for solar cells due to excellent photoelectric properties. However, when ZnO is used as electron transport layers (ETLs) in perovskite solar cells (PSCs), the occurred deprotonation reactions can easily lead to the decomposition of perovskite layer. Herein, we reported a simple and controllable low-temperature strategy to overcome above problem for achieving high-efficient and stable ZnO based planar PSCs, i.e. the colloidal PbS QDs and tetrabutylammonium iodide (TBAI) was sequentially spin-coated on ZnO ETLs and then mild post-annealing process was carried out to obtaining ZnO/PbS-TBAI compact layer. Due to the iodine ligands from TBAI, the PbS-TBAI films act as both surface wetting control layer and electric dipole layer to adjust the crystal growth of perovskite films and charge behavior within devices. The better non-wetting surface of ZnO/PbS-TBAI ETLs improves the crystallization of the perovskite films by suppressing heterogeneous nucleation. And the unique energy level alignment of ZnO/PbS-TBAI induced by tunable surface dipole moment of TBAI boosted hetero-interface charge extraction of PSCs. Consequently, the optimized ZnO/PbS-TBAI based PSCs exhibits the power conversion efficiency (PCE) of 20.53 %, which is the champion PCE of ZnO PSCs with MAPbI 3 as the absorption layer. Stability tests also proved that the PCE of ZnO/PbS-TBAI based PSCs remains more than 86 % after exposure to 40 % humidity for 30 days, which is much more superior to that of control device. We firstly used iodination PbS QD films in this work to achieve higher photovoltaic performance in ZnO based PSCs, which prompts the further application of QDs materials within optoelectronic devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Inorganic HAuCl 4 doping combined organic NPB post-treatment strategy was proposed. • High PCE of 19.20% for Au@PEDOT:PSS/NPB PSCs is achieved on rigid substrate. • Flexible Au@PEDOT:PSS/NPB PSCs achieve 14.04% PCE with strong wrinkle resistance. • Improved hysteresis and stability of PSCs are realized via synchronous regulation. The further improvements in optoelectronic properties, hydrophobicity of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hole transport layers, as well as regulation of defect states within devices are essential to promote the continued development of inverted p-i-n rigid and flexible planar perovskite solar cells (PSCs). However, the strong hygroscopicity, poor surface morphology, lower work function and coil configuration of pristine PEDOT:PSS films are detrimental to their own performance and growth dynamics process of perovskites, often resulting in sever energy losses and poor device performance. Herein, hydrogen tetrachloroaurate (III) hydrate (HAuCl 4 ·3H 2 O) additive is combined with a conductive N,N'-Bis-(1-naphthalenyl)-N,N'-bis-phenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) buffer layer to boost device performance by systematically modulating PEDOT:PSS and perovskite film. Wherein, the redox reaction between PEDOT:PSS and HAuCl 4 can cause phase segregation of PEDOT:PSS, improving the hydrophobicity, electrical conductivity, work function and surface morphology of the films. The reduced gold nanoparticles will produce localized surface plasmon resonance effects, thus enhancing the utilization of solar radiation by perovskite films. Furthermore, the suitable energy level alignment of NPB layer relative to perovskite and Au@PEDOT:PSS films will sufficiently exploit the dissociative excitons to facilitate effective hole transport, and the N atoms in NPB can also passivate defects at the interface by binding to uncoordinated Pb2+ ions, thereby reducing non-radiative open-circuit voltage loss and increasing short-circuit current density. A high power conversion efficiency (PCE) of 19.20% can be achieved for MA 0.85 FA 0.15 PbI 3 based p-i-n PSCs with negligible hysteresis and enhanced stability of devices. Similarly, the corresponding flexible device achieves a PCE of 14.04% with improved crumpling durability throughout low temperature preparation conditions below 140 °C. Our work presents a facile method to prepare high-efficient inverted PSCs while achieving improved long-term device stability. [ABSTRACT FROM AUTHOR]

• We developed a "hillocks"-like random-textured perovskite (HRT-perovskite) absorber. • Crystallization kinetics and formation mechanisms of CB-induced HRT-perovskite absorbers have been proposed. • Proper volume CB promoted the construction of porous MAI-PbI 2 -DMSO intermediate structure. • Efficient light trapping was achieved by employing CB-induced HRT-perovskite absorbers. Efficient planar heterojunction perovskite solar cells (PSCs) with high-quality absorbers are promising for flexible-, semitransparent-, and tandem- photovoltaic applications. However, compared to mesoporous PSCs, planar perovskite absorbers tend to suffer from additional optical losses due to insufficient light harvesting. Accordingly, the design and fabrication of high-quality textured perovskite absorbers are promising to improve device performance. We developed a "hillocks"-like random-textured perovskite (HRT-perovskite) absorber using a facile chlorobenzene (CB) anti-solvent assisted spin-coating approach. The crystallization kinetics and formation mechanisms of CB-induced HRT-perovskite absorbers have been systematically explored, allowing us to gain insights into the role of CB, i.e. an appropriate volume of CB promotes the formation of a porous MAI-PbI 2 -DMSO intermediate structure. We show that the porous nature of the intermediate film provides sufficient space for lattice reconstruction and structure expansion during crystal growth, thus effectively improving the film and surface/interface quality, and, ultimately, the optoelectronic properties of the perovskite absorber. Moreover, the HRT-perovskite absorber exhibits excellent light-trapping capability and carrier mobility, due to its optimized surface roughness and longitudinally ordered grain boundary distribution. As a result, we obtained efficiencies of up to 20.03% from planar heterojunction PSCs fabricated using ~400 nm thick HRT-perovskite absorbers. The process exhibits very high reproducibility with 20 individual devices fabricated in one batch, achieving an average power conversion efficiency (PCE) of 19.00%. Finally, the whole fabrication process was conducted below 150 ℃, which is appropriate for a wide range of applications, such as flexible- and tandem- photovoltaic devices. [ABSTRACT FROM AUTHOR]

Electron transport layer (ETL) is one of the key functional layers for extracting carriers in perovskite solar cells (PSCs). SnO 2 with high electron mobility and excellent energy level matching with adjacent perovskites has been considered an ideal electron transport material with great application prospects. However, surface defects always exist on the SnO 2 films prepared by solution method, which will inevitably lead to non-radiation recombination at the interface of SnO 2 ETL/perovskite. To further improve the performance of PSCs, the defects should be effectively suppressed. Herein, an interfacial engineering strategy is adopted to eliminate the surface defects and improve the interface performance by passivating the SnO 2 electron transport layer with sodium L -ascorbate (SLA). After the SLA treatment, the interfacial defects of SnO 2 /perovskite film were reduced significantly and the electron transport was effectively facilitated by the denser SnO 2 layer, finally improving the power conversion efficiency (PCE) of PSCs. Besides, SLA neutralized the alkalinity of SnO 2 film, simultaneously improving the efficiency and stability of the device. As a result, the PCE of FA 0.74 MA 0.19 Cs 0.07 PbI 2.81 Cl 0.19 PSCs with active area of 0.09 cm2 was increased from 20.32 % to 22.70 %, and the larger area PSCs with active area 1.00 cm2 obtained a high PCE of 19.83 %. This work presents a convenient and effective passivation strategy for improving the ETL to promote the development of perovskite photovoltaic devices. [Display omitted] • Sodium L -ascorbate is introduced into ETL/perovskite interface. • The efficiency of charge extraction and transfer from perovskite layer to ETL is enhanced. • SLA-modified PSCs achieve a champion PCE of 22.70 % in small size (0.09 cm2) and 19.83 % in large size (1.00 cm2). • The optimal PSCs showed excellent stability under illumination. [ABSTRACT FROM AUTHOR]

The fragile framework of the organic–inorganic metal halide perovskite has been strengthened for improving the stability of the PSCs by a multifunctional 2-amino-acetamidobenzotrifluoride (called BDP) with –NH 2 , C=O, and -CF 3 groups, simultaneously yielding a high efficiency of 21.62% for MAPbI 3 -based solar cells. [Display omitted] • A novel BDP-perovskite composite was developed for efficient and stable PSCs. • The BDP improved perovskite quality by retarding crystallization process. • The perovskite framework is reinforced by forming N-H...F bond with BDP. • The PCE of the BDP-treated device increased to 21.62% with a high V oc of 1.21 V. Perovskite solar cells (PSCs) are one of the most prospective photovoltaic devices because of their excellent photoelectric properties, yet their stability remains challenging. Apart from the reported passivation or encapsulation strategies, reinforcing the inherent framework of the perovskite is recognized as a substantial approach to stabilizing the PSCs. Herein, a multifunctional 2-amino-acetamidobenzotrifluoride (called BDP) with –NH 2 , C = O, and -CF 3 moieties is meticulously screened to strengthen the perovskite framework. The electron-donating groups of the BDP (–NH 2 and C = O) can simultaneously modify the crystallization process and achieve passivation, which devoted to reducing defect density; -CF 3 is used as a hydrophobic chemical stabilizer to form a moisture-resistant layer on the perovskite surface and suppress the MA+ ion migration by forming a hydrogen bond. Notably, the presence of the BDP also achieves a better energy level matching at the perovskite/hole transfer layer interface. Consequently, the power conversion efficiency (PCE) of MAPbI 3 solar cells is remarkably improved from 18.47% to 21.62%. Compared with the control devices, the PCE remains relatively stable under harsh external environmental conditions. Furthermore, the BDP also inhibits the lead leakage of PSCs, which is conducive to environmental applications. [ABSTRACT FROM AUTHOR]

A supramolecular bridging strategy with 2, 5-diaminobenzotrifluorid (DTF) molecular binder as the repeating unit was introduced to form a supramolecular-perovskite composite. The supramolecular binder plays a role of bridging the perovskite crystal grains, passivating the traps states of the perovskite films and producing excellent environmental stability. [Display omitted] • A supramolecular bridging strategy with DTF as repeat unit was proposed. • Bridging effect induced by the S-DTF for perovskite films was revealed. • Moisture-resistant MAPbI 3 solar cells with excellent performance was achieved. • Photovoltaic performance of MAPbI 3 solar cells have been effectively improved. The manipulation of grain boundaries in polycrystalline perovskites is an indispensable consideration for the photovoltaic performance and environmental stability of solar cells, because perovskite films obtained by solution process will inevitably introduce many defects in the grain boundaries. Although additives based on small molecules have proven to be effective defect passivators, their high volatility and diffusibility cannot satisfy the stability requirements of perovskite films. As an upgraded approach, herein, we introduced a supramolecular bridging strategy with 2,5-diaminobenzotrifluorid (DTF) molecular binder as the repeating unit to form a supramolecular-perovskite composite. The supramolecular binder plays a role of bridging the perovskite crystal grains, passivating the traps states of the perovskite films and producing excellent environmental stability, which is superior to the conventional additive engineering. As a result, the power conversion efficiency of the MAPbI 3 solar cell has been significantly increased from 18.8% to 21.0 %. The perovskite solar cells with S-DTF maintaining 93% of their original efficiency for over 30 days (∼70% humidity) in air ambient without encapsulation, exhibiting an excellent long-term stability. This will inspire a wider range of ideas beyond the regular additive engineering for improving the performance of polycrystalline perovskite-based photoelectronic devices. [ABSTRACT FROM AUTHOR]

Photoelectric imbalance problems of rear transparent conductive electrodes (TCEs) limit the photovoltaic (PV) performance of bifacial planar heterojunction perovskite solar cells (PH–PSCs). We exploit the superior electrical advantages of 0-dimensional (0D) carbon quantum dots (C QDs), 1-dimensional (1D) silver nanowires (Ag NWs), and 2-dimensional (2D) ultrathin Ag films to develop a novel rear TCE with ideal photoelectric balance, i.e., Ag NW + C QD/Ag NW/molybdenum oxide (MoOx)/ultrathin Ag (denoted as A + C/A/M/A) rear TCE with a 0D/1D/2D composite structure. We show that C QDs fully fill the voids within the Ag NW network, which effectively accelerates the charge transfer/collection, thereby enhancing the PV output of PH-PSCs. Moreover, the film quality and photoelectric properties of the rear TCEs are further improved by depositing the MoOx/ultrathin Ag films onto the A + C composite network, which significantly improves PV performance. More importantly, MoOx is key to realizing the photoelectric balance of rear TCEs because it not only has excellent antireflection effects, but also promotes the formation of high-quality ultrathin Ag film. As a result, the efficiencies of the A + C/A/M/A-based PH-PSC under front and rear illuminations are 16.09% and 12.59%, respectively, which are superior to that of most reported Ag NW-based PSCs. [Display omitted] • A novel 0D/1D/2D composite rear TCE was constructed. • Photoelectric balance of the rear TCE was achieved. • MoOx promoted the formation of high-quality 2D ultrathin Ag films. • The effects of the rear TCEs on the photovoltaic parameters were clarified. [ABSTRACT FROM AUTHOR]

Hole transport layer plays a critical role in achieving high performance and stable inverted perovskite solar cells (PSCs). Doping has been proved to be an effective strategy to modify the electrical and optical properties of semiconductor oxides. Herein, rare earths (REs: Ce, Nd, Eu, Tb, and Yb) elements are systemically doped into the NiO x hole transport layer (HTL) via a simple solution-based method. The results demonstrate that the REs doping could considerably modify the compactness, conductivity, and band alignment of the NiO x HTL, leading to the highly improved permanence of the inverted PSCs. The PSCs using 3% Eu:NiO x HTL yielded the optimum power conversion efficiency of 15.06%, relatively improved 23.4% compared with the PSC using pristine NiO x HTL (12.20%). It also demonstrated much better long time stability. The improved photovoltaic properties of the device can be attributed to the more efficient charge extraction and suppressed interfacial recombination rate by the introduction of appropriate REs in the NiO x HTL. This work indicates that RE doping is a very effective and promising strategy to achieve adjustable hole extraction material for high and stable inverted PSCs. Image 1 • REs (Ce, Nd, Eu, Tb, Yb) ions were doped into NiO x HTLs via solution method. • PSC using 3% Eu:NiO x exhibited the best PCE of 15.6%, with 23.4% improvement. • The improvement was attributed to the improved conductivity and perovskite layer. [ABSTRACT FROM AUTHOR]