Efficient Inverted Perovskite Solar Cells Research Articles

Interface passivation with Ti3C2Tx-MXene doped PMMA film for highly efficient and stable inverted perovskite solar cells

PMMA:MXene passivates a perovskite/ETL interface boosting performance and stability. Less interfacial defects increase the charge lifetime resulting in a higher density of photo-generated carriers.

Simultaneous realization of bulk and interface regulation based on 2,4-diamino-6,7-diisopropylpteridine phosphate for efficient and stable inverted perovskite solar cells

A facile interface strategy based on 2,4-diamino-6,7-diisopropylpteridine phosphate is proposed to simultaneously regulate the bulk and interface recombination loss in the inverted perovskite solar cells.

Interfacial engineering with trivalent cation for efficient and stable inverted inorganic perovskite solar cells

Metal halide inorganic perovskites with excellent thermal stability and ideal bandgaps are suitable for constructing inverted top subcells for tandem devices. However, facts such as defect-induced nonradiative recombination, interfacial energy...

Suppressing surface and interface recombination to afford efficient and stable inverted perovskite solar cells.

The top surface of the perovskite layer and the interface with the electron transporting layer play a key role in influencing the performance and operational stability of inverted perovskite solar cells (PSCs). A deficient or ineffective surface passivation strategy at the perovskite/electron transport layer interface can significantly impact the efficiency and scalability of PSCs. This study introduces phenyl dimethylammonium iodide (PDMAI2) as a passivation ligand that exhibits improved chemical and field-effect passivation at the perovskite/C60 interface. It was found that PDMAI2 not only passivates surface defects and suppresses recombination through robust coordination but also repels minority carriers and reduces contact-induced interface recombination. The approach leads to a twofold reduction in defect densities and photoluminescence quantum yield loss. This approach enabled high power conversion efficiencies (PCEs) of 25.3% for small-area (0.1 cm2) and 23.8% for large-area (1 cm2) inverted PSCs. Additionally, PDMAI2 passivation enabled PSCs to demonstrate steady operation at 65 °C for >1200 hours in an ambient environment.

Combining component screening, machine learning and molecular engineering for the design of high-performance inverted perovskite solar cells

To develop efficient and stable inverted perovskite solar cells, we describe an innovative strategy that combines component screening, machine learning and molecular engineering.

Facile Posttreatment of Self‐Assembled Monolayers for Efficient Inverted Perovskite Solar Cells

The application of self‐assembled molecules (SAM) allows inverted‐structural perovskite solar cells to accomplish high efficiencies, by virtue of their high hole conductivity and negligible parasitic absorption. However, amphiphilic SAM tend to form spherical micelles in commonly used alcoholic solvents, leading to aggregation in the resulting film. In addition, hydrophobic groups of SAM are exposed to the surroundings after being deposited on transparent substrates, responsible for the poor crystallinity of perovskite and interface quality. Therefore, it is important to study the treatment of SAM layers or SAM/perovskite interfaces for better device performance. Herein, dual regulation of SAM and perovskite is achieved via a facile posttreatment by formamidinium chloride (FACl) solution in N,N‐Dimethylformamide. First, by taking advantage of solvent rinsing, aggregations at the surface of SAM layer are alleviated. Second, FACl on the top of the SAM layer assists the crystallization of perovskite through interaction with PbI2 and reduces the defect concentration via passivating the halide vacancies at the buried interface of the device. With a more uniform SAM layer, better‐crystallized perovskite, and suppressed nonradiative recombination between them, the power conversion efficiency of the target device is improved by 20%.

The synergistic strategy of hexaazatrinaphthylene-cyanoindone-based electron transporting material enabling efficient and stable inverted perovskite solar cells

The synergistic strategy of hexaazatrinaphthylene-cyanoindone-based electron transporting material enabling efficient and stable inverted perovskite solar cells

Surface Modulation via Conjugated Bithiophene Ammonium Salt for Efficient Inverted Perovskite Solar Cells.

The metal halide perovskite absorbers are prone to surface defects, which severely limit the power conversion efficiencies (PCEs) and the operational stability of the perovskite solar cells (PSCs). Herein, trace amounts of bithiophene propylammonium iodide (bi-TPAI) are applied to modulate the surface properties of the gas-quenched perovskite. It is found that the bi-TPAI surface treatment has negligible impact on the perovskite morphology, but it can induce a defect passivation effect and facilitate the charge carrier extraction, contributing to the gain in the open-circuit voltage (Voc) and fill factor. As a result, the PCE of the gas-quenched sputtered NiOx-based inverted PSCs is enhanced from the initial 20.0% to 22.0%. Most importantly, the bi-TPAI treatment can largely alleviate or even eliminate the burn-in process during the maximum power point tracking measurement, improving the operational stability of the devices.

π-Interactions suppression of buried interface defects for efficient and stable inverted perovskite solar cells

Poly(triarylamine) (PTAA) is commonly utilized as a hole transport layer due to suitable band alignment with perovskite layer, but its poor infiltration of perovskite precursors easily leads to buried interface defects. Here, we propose a molecular bridging strategy to bridge PTAA and perovskite layer by employing the special π-interactions molecule of 2, 4, 6-tris(4-aminophenyl)-s-triazine (TAPT). The amidogen of TAPT can produce H-π bond with the benzene ring in PTAA to make them bind tightly, thus fixing the fractures and reducing defect sites in PTAA, while the triazine ring of TAPT can interact with uncoordinated Pb2+ to form π-Pb2+ bond and passivate Pb2+ defects. In addition, the TAPT assists in achieving a pinhole-free buried interface, which enhances interfacial carrier transport and suppresses interfacial nonradiative recombination. Eventually, the device with TAPT achieves the champion efficiency of 24.57 %. The devices with TAPT have greatly improved operating and thermal stability, sustaining 89.7 % of the initial efficiency after 1500 h of maximum power point tracking and 91.9 % of the initial efficiency after 1065 h of 85 °C heat treatment. This approach focuses on the important role of the π-interactions at the buried interface to develop efficient and stable perovskite solar cells.

Stable and Efficient Inverted Perovskite Solar Cells Enabled by Structural Design of Lewis Base Molecules

Stable and Efficient Inverted Perovskite Solar Cells Enabled by Structural Design of Lewis Base Molecules

Functional layers in efficient and stable inverted tin-based perovskite solar cells

Functional layers in efficient and stable inverted tin-based perovskite solar cells

Ionic Liquid-Induced Multisite Synergistic Interactions for Highly Efficient Inverted Perovskite Solar Cells.

The interfacial properties of p-i-n inverted perovskite solar cells (PSCs) play a key role in further improving the photovoltaic performance of PSCs. Herein, multisite synergistic interactions were constructed using ionic liquids (ILs) prepared by mixing urea and choline chloride (ChCl) to substantially improve the interfacial properties of inverted PSCs. Systematically theoretical calculations and experimental studies are comprehensively performed, which reveal that the C═O···Pb2+ coordination interaction, N-H···I hydrogen bond, and Cl-Pb bond could be simultaneously formed between the perovskites and IL, and Ch in IL could interact with the perovskite by occupying the formamidinium site. Meanwhile, -OH/π and -NH/π interactions could be formed between -OH and -NH in IL and the phenyl group in PTAA, respectively. These multisite synergistic interactions are beneficial to improve the perovskite film quality and interfacial properties of inverted PSCs, which could greatly suppress nonradiative recombination within the PSCs. Consequently, the inverted PSCs show an impressive efficiency of 22.4% and an excellent electroluminescence efficiency of 3.7%.

Surface passivation by multifunctional carbon dots toward highly efficient and stable inverted perovskite solar cells

Interfacial imperfections between the perovskite layer and the electron transport layer (ETL) in perovskite solar cells (PSCs) can lead to performance loss and negatively influence long-term operational stability. Here, we introduce an interface engineering method to modify the interface between perovskite and ETL by using multifunctional carbon dots (CDs). C = O in the CDs can chelate with the uncoordinated Pb2+ in the perovskite material, inhibit interfacial recombination, and enhance the performance and stability of device. In addition, –OH in CDs forms hydrogen bonds with I− and organic cation in perovskite, inhibiting light-induced I2 release and organic cation volatilization, causing irreversible degradation of perovskite films, thereby enhancing the long-term operational stability of PSCs. Consequently, we achieve the champion inverted device with an efficiency of 24.02%. The CDs-treated PSCs exhibit high operational stability, and the maximum power point tracking only attenuates by 12.5% after 1000 h. Interfacial modification engineering supported by multifunctional quantum dots can accelerate the road to stable PSCs.

Pre‐buried Interface Strategy for Stable Inverted Perovskite Solar Cells Based on Ordered Nucleation Crystallization

AbstractThe buried interface has important effect on carrier extraction and nonradiative recombination of perovksite solar cells (PSCs). Herein, to inactivate the buried interfacial defects of perovskite and boost the crystallization quality of perovskite film, 3‐amino‐1‐adamantanol (AAD) serves as a pre‐buried interface modifier on nickel oxide (NiOx) surface to regulate the nucleation and crystallization process of perovskite precursor. The amino and hydroxyl groups in AAD molecule can synchronously coordinate with nickel ion (Ni3+) in NiOx and lead ion in perovskite, respectively. The dual action favors the ordered arrangement of AAD molecules between NiOx and perovskite, which not only enhances hole extraction in hole transport layer, but also provides active sites for homogeneous nucleation. Furthermore, AAD modifier blocks the unfavorable reaction between Ni3+ and perovskite, and effectively passivates the buried interfacial defects. The optimal inverted PSCs achieve a champion power conversion efficiency of 22.21% with negligible hysteresis, favorable thermal, optical, and long‐term stability. Thus, this strategy of modulating perovskite nucleation and crystallization by pre‐buried modifier is feasible for achieving efficient and stable inverted perovskite solar cells.

Synergistic Passivation With Phenylpropylammonium Bromide for Efficient Inverted Perovskite Solar Cells.

Inverted perovskite solar cells (PSCs) are a promising technology for commercialization due to their reliable operation and scalable fabrication. However, in inverted PSCs, depositing a high-quality perovskite layer comparable to those realized in normal structures still presents some challenges. Defects at grain boundaries and interfaces between the active layer and carrier extraction layer seriously hinder the power conversion efficiency (PCE) and stability of these cells. In this work, it is shown that synergistic bulk doping and surface treatment of triple-cation mixed-halide perovskites with phenylpropylammonium bromine (PPABr) can improve the efficiency and stability of inverted PSCs. The PPABr ligand is effective in eliminating halide vacancy defects and uncoordinated Pb2+ ions at both grain boundaries and interfaces. In addition, a 2D Ruddlesden-Popper (2D-RP) perovskite capping layer is formed on the surface of 3D perovskite by using PPABr post-treatment. This 2D-RP perovskite capping layer possesses a concentrated phase distribution ≈n = 2. This capping layer not only reduces interfacial non-radiative recombination loss and improves carrier extraction ability but also promotes stability and efficiency. As a result, the inverted PSCs achieve a champion PCE of over 23%, with an open-circuit voltage as high as 1.15V and a fill factor of over 83%.

Multi-functional buried interface engineering derived from in-situ-formed 2D perovskites using π-conjugated liquid-crystalline molecule with aggregation-induced emission for efficient and stable NiOx-based inverted perovskite solar cells

The poor and limited-functional NiOx/perovskite buried interface has hindered the development of NiOx-based perovskite solar cells (PSCs). Herein, a π-conjugated liquid-crystalline organic spacer with aggregation-induced emission (AIE), (Z)-2-([1,1′-biphenyl]-4-yl)-3-(4-(3-aminopropoxy)phenyl)acrylonitrile (BPCSA), is employed for the multi-functional NiOx/perovskite buried interface engineering. The functional groups of BPCSA spacer can coordinate with NiOx and induce the in-situ formation of 2D perovskite at the NiOx/perovskite interface. The in-situ-formed 2D perovskite interlayer can passivate interface defects, strengthen interface interconnection and optimize energy level alignment between NiOx and 3D perovskites. More markedly, the π-conjugated liquid-crystalline molecular structure and AIE property of BPCSA spacer can guide the high-quality crystal growth of upper 3D perovskite films, release interfacial strain, facilitate interfacial carrier transport and realize efficient photosensitization process concurrently. Consequently, such 3D/2D PSCs can acquire a champion power conversion efficiency (PCE) of 23.45% with improved stability. Besides, high-performance flexible 3D/2D PSCs are also successfully demonstrated.

A Novel Anthracene Derivative Used as Cathode Interlayer for Efficient Inverted Perovskite Solar Cell

Metal halide hybrid perovskite solar cells have recently emerged as a highly cost‐effective photovoltaic technology. The cathode interlayer plays a critical role in aligning energy levels and promoting charge extraction in inverted perovskite solar cells. Herein, a novel multinitrogen derivative interlayer, Anth‐hpp2, is designed and synthesized consisting of 1,1'‐(4‐(9,10‐di(naphthalen‐2‐yl)anthracen‐2‐yl)pyridine‐2,6‐diyl)bis(1,3,4,6,7,8‐hexahydro‐2H‐pyrimido[1,2‐a] pyrimidine), between the PCBM and top Ag electrode. The superbase group in Anth‐hpp2 effectively contacts the silver electrode, reducing the work function of Ag. Consequently, the power conversion efficiency of the Anth‐hpp2‐based device improved from 16.05% to 20.37%, along with enhancements in short‐circuit current and fill factor. The stabilities of perovskite solar cells are measured with Anth‐hpp2 under N2 storage, and the device efficiency with Anth‐hpp2 decayed by only 5% after fabrication for approximately 2500 h, which is five times that of the control device. This study provides original insights into designing new cathode interlayer materials.

Solution‐Processed Metal Ion Polyelectrolytes as Hole Transport Materials for Efficient Inverted Perovskite Solar Cells

AbstractDespite achieving high efficiencies over a short time, further streamlining of hybrid lead‐halide perovskite solar cell (PSC) designs is necessary for their commercial viability. In this contribution, a new class of interfacial hole transporting layer (HTL) materials consisting of anionic polyelectrolytes comprising polystyrene sulfonate (PSS) with metal cations are explored. These materials represent alternatives to metal oxides, combining characteristics of metal oxides with the facile preparation and desirable film‐forming characteristics of polyelectrolytes. Polyelectrolytes with cations including Li, Mg, V, Mn, Co, Ni, Cu, Zn, Pd, Ag, In, Cs, and Pb as HTLs in inverted PSCs are explored. A range of positive and negative effects is observed for different metal cations, which are attributed to differences in the physical properties of the polyelectrolytes, and their influence on the electronic band structure of devices and the crystal qualities of the perovskite absorber. Ni and Cu polyelectrolytes created p‐type contacts at the anode of PSCs, improving device performance. These materials are believed to have potential in other types of devices as well. This type of metal:PSS polyelectrolyte has not yet been widely investigated, however, it is shown that it constitutes a simple and economic strategy to engineer energy band structures in perovskite devices.

Dual Cross‐Linked Functional Layers for Stable and Efficient Inverted Perovskite Solar Cells

The operational stability of p–i–n perovskite solar cells (PSCs) is dramatically subjected to the quality of the perovskite light harvester and the interface layer atop the perovskite. Herein, a dual crosslinked functional layer strategy of using the versatile polydimethylsiloxane as an additive both in the perovskite layer and in phenyl‐C61‐butyric acid methyl ester interface layer, to improve the device tolerance against light, thermal, humidity, and bending stress, is reported. As a result, a promising power conversion efficiency of 21.6% (stabilized at 21.3%) for nickel oxide‐based p–i–n PSCs is achieved. In addition, the unencapsulated devices maintain 97% of their initial efficiencies after continuous operation under 1 sun equivalent illumination at 60 °C with maximum power point tracking for 1000 h and 80% of their initial efficiencies exposed in ambient air for 500 h. The application of the aforementioned strategy in the flexible device also improves the bending mechanical stability, of which the corresponding flexible devices maintain 85% of their initial efficiencies after 1000 cycles at a radius of 8 mm.

Minimizing buried interfacial defects for efficient inverted perovskite solar cells.

Controlling the perovskite morphology and defects at the buried perovskite-substrate interface is challenging for inverted perovskite solar cells. In this work, we report an amphiphilic molecular hole transporter, (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphonic acid, that features a multifunctional cyanovinyl phosphonic acid group and forms a superwetting underlayer for perovskite deposition, which enables high-quality perovskite films with minimized defects at the buried interface. The resulting perovskite film has a photoluminescence quantum yield of 17% and a Shockley-Read-Hall lifetime of nearly 7 microseconds and achieved a certified power conversion efficiency (PCE) of 25.4% with an open-circuit voltage of 1.21 volts and a fill factor of 84.7%. In addition, 1-square centimeter cells and 10-square centimeter minimodules show PCEs of 23.4 and 22.0%, respectively. Encapsulated modules exhibited high stability under both operational and damp heat test conditions.