Performance Of PSCs Research Articles

Innovative Materials for Lamination Encapsulation in Perovskite Solar Cells

AbstractPerovskite solar cells (PSCs), as the forefront of third‐generation solar technology, are distinguished by their cost‐effectiveness, high photovoltaic efficiency, and the flexibility of their bandgap tunability, positioning them as formidable contenders in the photovoltaic market. However, the stability of PSCs remains a significant barrier to their widespread commercialization. Lamination encapsulation is identified as a pivotal intervention to enhance the durability of PSCs under external environmental stress. This review initiates with an in‐depth exploration of the degradation phenomena in PSCs, triggered by environmental stressors such as water, oxygen, light, and heat. This analysis lays bare the degradation mechanisms, thereby highlighting the specific demands for effective encapsulation materials. Subsequently, the review presents a systematic discourse on the latest developments in encapsulation materials, dissecting their molecular structures and linking these to their physical properties and performance in encapsulation applications. The narrative concludes by charting potential future research pathways intended to refine and enhance the encapsulation performance of PSCs, offering several routes for overcoming current limitations and propelling PSCs toward their full commercial potential.

Post-Treating Grain Boundaries and Surface Defects by Long-Chain Polymer for Highly Efficient and Stable Perovskite Solar Cells.

Grain boundaries (GBs) and surface defects within perovskite films are inherent challenges that affect the photovoltaic performance of perovskite solar cells (PSCs. In this work, Nylon 11 (N11) is utilized, a long-chain polymer, for post-treating the GBs and surface defects within FAPbI3 films. The multifunctional groups of N11 exhibit unique passivation abilities, enabling self-regulation and selective correction of reverse-charged defects. Post-treating with N11 results in high-quality FAPbI3 films characterized by tight GBs and low surface defect density. Despite fabrication under full open-air conditions, the N11 post-treatment significantly enhances the power conversion efficiency (PCE) value of FAPbI3 PSCs, increasing it from the reference value of 21.89% to 23.54%. Importantly, the long alkyl chain present in N11 significantly enhances the humidity stability of the PSCs. Unencapsulated PSCs treated with N11 maintain 89% of their initial PCE after exposure to air with 30% relative humidity (RH) for 1000h, demonstrating resilience to elevated humidity levels. This work highlights the substantial improvement in the photovoltaic performance of PSCs achieved through the post-treatment with N11.

Defect passivation engineering for achieving 4.29% light utilization efficiency MA-free wide-bandgap semi-transparent perovskite solar cells

Wide-bandgap perovskite materials are a great candidate for semitransparent perovskite solar cells (ST-PSCs) due to their tunable bandgap, outstanding transparency, and excellent photovoltaic performance. Though Br-rich perovskite can widen the bandgap, Br influences the crystallization dynamic speed leaving small perovskite grain sizes and high defects. Surface passivation engineering has been one of the best choices to suppress defects caused by the rapid crystallization of Br-rich perovskites. Herein, we applied MA-free perovskite as a light absorber because of the erratic thermal aging of MA-containing perovskites and selected phenethylammonium iodide (PEAI) and 4-trifluoro phenylethylammonium iodide (CF3PEAI) as passivation materials for improving the performance of opaque PSCs and ST-PSCs. Consequently, CF3PEA possesses a larger dipole moment. It has been demonstrated to exhibit a stronger binding energy with the substrate than PEA by density functional theory (DFT) calculations. This enhanced molecular interaction underpins the performance improvements in our solar cells, which manifests as an inverted planar structure opaque PSCs with 1.78 eV bandgap achieve a power conversion efficiency (PCE) of 17.09 % with excellent stability. A PCE of 17.17 % with 25 % average visible-light transmittance (AVT) and 4.29 % light utilization efficiency (LUE) of ST-PSCs is achieved by further optimizing the fabrication process of the buffer layer for protecting the perovskites from the damage of ITO sputter. Meanwhile, a four-terminal tandem solar cell with ST-PSC and silicon-based passivated emitter rear cell (PERC) obtains a PCE of 26.28 %. This work provides a feasible way to fabricate high-performance ST-PSCs with limited materials and preparation conditions.

Ultrafast hole transfer mediated by a conjugated self-assembled molecule enables efficient and stable wide-bandgap perovskite solar cells

Charge accumulations and electron recombination at the interfaces between perovskites and charge transporting materials are two critical factors significantly hindering the power conversion efficiency (PCE) and device stability of wide-bandgap perovskite solar cells (WBG PSCs). Herein, we tailor-made a self-assembled molecule (SAM), termed XS13, featuring an enlarged π-donor and a π-linker, to regulate the interface carrier dynamics in ∼1.8 eV WBG PSCs. Ultrafast spectroscopy clearly demonstrated that the XS13 facilitated the rapid extraction and transfer of photo-generated holes compared to the reference SAM-2PACz. Consequently, WBG PSCs based on XS13 achieved an outstanding PCE of up to 19.20 %, surpassing that of control devices (16.41 %). Furthermore, XS13-based WBG PSCs exhibited a remarkable suppression of light/electricity-induced halide ions migration, leading to significantly improved device stability. Our findings offer a new strategy for the rational design of hole transporting molecules with controlled properties to enhance device performance of PSCs.

Boosted device performance of perovskite solar cells via KI processing additives

AbstractPerovskite solar cells (PSCs) have attracted great attention in both academic and industrial sectors in the past years. Studies demonstrated that processing additive engineering was a facile way to improve the crystallinity and minimize the defect of metal halide perovskites (MHPs). In this study, we report efficient and stable PSCs, where the MHPs thin film is processed with KI additives. It is found that the KI processing additives could not only enhance the crystallization and suppress the defects of MHP thin film, but also boost charge transport, suppress non-radiative recombination, and enhance the hydrophobic properties of MHP thin film. As a result, the PSCs based on the MHPs thin film processed with KI additives exhibit more than 10% enhancement in efficiency and dramatically boosted stability compared to that based on pristine MHPs thin film. Our results indicated that the MHPs processed with processing additives are a simple engineering technique to boost the device performance of PSCs.

Enhancing efficiency in inverted perovskite solar cells: The role of dual-site binding ligands

Despite the rapid progress in efficiency, PSCs encounter substantial challenges regarding durability and scalability. Inverted p-i-n PSCs provide enhanced long-term operating stability over the conventional n-i-p structures but lag in PCE (Park and Zhu, 2020 [3]). This limitation is mainly due to the interface between the perovskite light-absorbing layer and charge transport materials, where energy band misalignment and energy level pinning hinder PCE. Furthermore, surface defects exacerbate these constraints. In the endeavor to improve performance of PSCs, surface passivation is crucial for reducing nonradiative recombination at the interface. A recent study by Chen et al., published in the journal Science, introduces an innovative interface passivation strategy for p-i-n PSCs that could set a new benchmark for efficiency and stability (Chen et al., 2024 [4]). This commentary assesses the potential impact of dual-site-binding ligands on PSCs and anticipates their transformative effect on the field.

Simulation‐Based Performance Analysis of Lead‐Free Bismuth Perovskite Solar Cells: A Comparative Study of Cs3Bi2I9 and (CH3NH3)3Bi2I9 ‐based Perovskite Solar Cells

AbstractPerovskite solar cells (PSCs) have emerged as promising candidates in PV research due to their exceptional photovoltaic properties. However, the toxicity and environmental concerns associated with lead‐based perovskites have led to the exploration of lead‐free alternatives. In this study, the performance of lead‐free bismuth PSCs, specifically PSCs based on Cesium Bismuth Iodide (Cs3Bi2I9) and Methyl Ammonium Bismuth Iodide (MA3Bi2I9), is investigated. Numerical simulations using the solar cell capacitance simulator (SCAPS) are conducted to comprehensively analyze the influence of key parameters, including the band‐to‐band radiative recombination rate, the absorber layer defect density, the absorber layer/electron transport layer (ETL) interface defect density, the absorber layer/hole transport layer interface (HTL) defect density, operating temperatures, and series and shunt resistances, and to optimize the proposed PSCs accordingly. The simulation results demonstrate a significant impact of these key parameters on the performance of Cs3Bi2I9 and MA3Bi2I9 PSCs. The optimized Cs3Bi2I9‐based PSC exhibited notable performance characteristics, including a PCE of 13.81%, a Voc of 1.16 V, a Jsc of 18.14 mA cm−2, and FF of 65.51%. In contrast, the MA3Bi2I9‐based PSC demonstrated relatively lower performance, with a PCE of 11.82%, Voc of 1.14 V, Jsc of 18.06 mA cm−2, and FF of 57.33%. The study on the defect density at the interfaces revealed the performance of PSCs is predominantly influenced by defects at the front interface (ETL/Absorber) rather than the rear interface (HTL/Absorber). These results provide valuable insights for the experimental design and optimization of lead‐free bismuth PSCs.

Optimization of the performance of CsPbI2Br perovskite solar cells in air by adding polyethylene-graft-maleic anhydride and its mechanism

In this study, by adding Polyethylene-graft-maleic anhydride (PGMA) to the inorganic CsPbI2Br perovskite film, the coordination bonds and hydrogen bonds between PGMA and CsPbI2Br cooperate to passivate defects, regulate energy level and stabilize the perovskite structure and eventually improve the device performance. We systematically study the effects of PGMA addition on the morphology, structure, light absorption, defect concentration and carrier lifetime, hydrophobicity, and optical stability and room temperature black phase stability of CsPbI2Br films, and the photoelectric performance and air stability of PSCs, as well as their mechanism. The experimental results show that the addition of 3 wt% of PGMA greatly improves the photoelectric conversion efficiency (PCE) of CsPbI2Br PSCs by 40.19 % because of the synergistic passivation effects and energy level tuning. The hydrogen bonds between –CH2 in PGMA and I−/Br− in CsPbI2Br, along with the coordination of carbonyl groups with Cs+/Pb2+, improve carrier transport and collection by inactivating flaw and managing the level, reducing the non-radiative recombination losses. In addition, the PSCs with 3 wt% of PGMA maintain 80 % of their initial efficiency even after 600 h in high humidity air environment due to the synergistic effect of coordination bonds and hydrogen bonds. Our study provides valuable insights into the use of PGMA to improve the performance of all-inorganic CsPbI2Br PSCs and the practicality of perovskite solar cells.

A novel chain-like conjugated donor-π-acceptor molecular additive for highly efficient and stable perovskite solar cells

In donor-π-acceptor (D-π-A) molecules, the coordination ability of the acceptor can be enhanced by the directed movement of delocalized electrons (DEs) on the π-bridge. However, the conventional aromatic ring as π-bridge limits the number of DEs due to the structural characteristic, which restrict the coordination ability of the acceptor, and there is still a lack of research on this issue. Herein, we proposed a chain-like conjugated π-bridge design strategy to address this issue. The Astaxanthin with eleven contiguous C − C = C fragments was selected as a chain-like D-π-A additive for perovskite films. Twenty-two DEs in such chain-like bridge can move towards the C = O group by the D-π-A effect within Astaxanthin, which increases the electron cloud density of C = O group so that enhances its coordination capacity with cations. Ultimately, the Astaxanthin-based device achieved a champion power conversion efficiency (PCE) of 24.43 % and maintained more than 95 % and 91 % of initial PCE for aging 1000 h in dry air (RH < 1 %) and atmosphere (RH = 20 ∼ 30 %), respectively. This work provides a novel strategy to break the restriction of aromatic rings to DEs, which provides theoretical and experimental guidance for further designing chain-like D-π-A additives with strong defect passivation ability to boost photovoltaic performance of PSCs.

Fluorination effects on bithiophene bridged hole transporting materials for perovskite solar cells

ABSTRACT The use of hole transporting material (HTM) remains indispensable for efficient charge extraction in perovskite solar cells. In this work, a series of small-molecule HTMs are designed by introducing fluorine atoms into the central part of 2,2′-bithiophene core. The effect of fluorination on the photophysical, electrochemical, and hole transport properties is systematically explored using Quantum chemistry calculation. The Calculated results reveal that all the highest occupied molecular orbitals (HOMOs) and the lowest unoccupied molecular orbitals (LUMOs) of the studied molecules are well matched with the energy band structure of perovskite. Three fluorine substituted hole-transporting materials possess lower reorganisation energy than the reference molecule BT-MTP. The higher mobility and matched energy levels of predicted HTMs are beneficial for improving the performance of PSCs. All the designed HTMs display higher hole mobility than those of the BT-MTP. Especially, molecule DFBT-p-MTP exhibits better optical properties and stability, indicating that fluorination is an effective strategy to improve the performance of the device in real application. This work provides an avenue for designing low-cost small molecule HTMs for high-performance perovskite solar cells.

Tailoring the Buried Interface by Dipolar Halogen-Substituted Arylamine for Efficient and Stable Perovskite Solar Cells.

Improving the quality of the buried interface is decisive for achieving stable and high-efficiency perovskite solar cells. Herein, we report the interface engineering by using dipolar 2,4-difluoro-3,5-dichloroaniline (DDE) as the adhesive between titanium dioxide (TiO2) and MAPbI3. By manipulation of the anchoring groups of DDE, this molecule not only passivated defects of TiO2 but also optimized the energy level alignment. Furthermore, the perovskite film on the modified TiO2 surface showed improved crystallinity, released residual stress, and reduced trap states. Therefore, these benefits directly contribute to achieving a power conversion efficiency of up to 22.10%. The unencapsulated device retained 90% of initial power conversion efficiencies (PCE) after continuous light illumination for 1000 h and 93% of initial PCE after exposure to air with a relative humidity of 30-40% for over 3000 h. Moreover, the performance of PSCs based on FA0.15MA0.85PbI3 has also increased from 20.48 to 23.51%. Our results demonstrate the effectiveness and universality of dipolar halogen-substituted arylamine (DDE) for enhancing PSC performance.

Applications of Emerging Metal and Covalent Organic Frameworks in Perovskite Photovoltaics: Materials and Devices

AbstractPerovskite solar cells (PSCs) have emerged as the next generation photovoltaic technology due to their high power conversion efficiency and solution‐based fabrication process. The performance of PSCs relies on the composition of each layer and the interface properties between layers. Hence, the integration of novel materials into PSCs presents a viable strategy for enhancing device performance. Metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) have recently emerged as promising materials for improving the efficiency and stability of PSCs. These materials offer a diverse range of tunable physicochemical properties and functionalities. This comprehensive review aims to provide an in‐depth summary of the progress in utilizing MOFs/COFs in PSCs. The review covers key aspects such as their electronic properties, synthesis methods, and various applications within PSCs, including their role as different components and their potential as lead absorbents. Finally, the review outlines important challenges and highlights future prospects for advancing this technology.

Multifunctional chemical anchors achieve a boosted fill factor and mitigate ion migration of high-stability perovskite solar cells.

To date, it is urgent to produce perovskite films with comparative or even better morphologies in an open-air environment. Unfortunately, a substantial number of trap states on the grain surface, especially the grain boundaries (GBs) of a perovskite layer, can bring about significant deterioration in the performance of PSCs. Trap-induced carrier recombination directly exerts a detrimental influence on the carrier collection efficiency and electronic properties of a perovskite active film. Herein, 4(5)-iodoimidazole (4II), a small organic molecule agent, was introduced to passivate the surface and bulk traps of the active film, which resulted in a controlled morphology, improved carrier extraction and suppressed ion migration for the devices fabricated in a relatively humid and O2-containing environment. Conductive atomic force microscopy (C-AFM) and Kelvin probe force microscopy (KPFM) measurements were applied to study trap passivation and suppression of ion migration across the GBs of perovskite films. The results manifest that the -CN group preferably bonds with the less-coordinated Pb2+ and the -NH- group favorably forms hydrogen bonds with the uncoordinated I-. As a result, the champion device delivered a significantly boosted power conversion efficiency from 17.22% to 20.95%, with an improved fill factor (FF) from 70.54% to 80.40%, and improved ambient stability of the unencapsulated device. This study may probe research insight into the design of passivators with synergistic effects for morphology control and reduction of carrier recombination loss for equally efficient perovskite photovoltaics fabricated in ambient air.

Probing the key roles of the back interface in the performance of carbon-based hole-transport-layer free perovskite solar cells

The key roles of perovskite films in the photovoltaic performance of carbon-based PSCs employing various absorbers were comprehensively studied and elucidated.

Solution fabrication methods and optimization strategies of CsPbBr3 perovskite solar cells

To date, various optimization strategies have been performed to enhance the performance of CsPbBr3 PSCs, such as additive engineering, interface engineering, HTL optimization and so on, and the best efficiency has reached 11.08%.

Polymer additive-promoted porous PbBr2 layer for fabricating high-performance carbon-based CsPbIBr2 perovskite solar cells through a two-step sequential deposition process

A PEG-assisted two-step sequential deposition process considerably enhances the CsPbIBr2 perovskite quality and promotes the photovoltaic performance of CsPbIBr2 PSCs.

Conductive chelating agent-treated electron transfer layers for environmentally friendly and efficient perovskite solar cells

A multifaceted conductive chelating agent, sodium p-styrenesulfonate (SSS), is incorporated into SnO2 precursor solution to improve the performance of PSCs and provide in situ suppression of lead leakage by chelating with dissociative Pb2+.

Exploring Optoelectronic‐Thermal Coupling in Perovskite Solar Cells Utilizing Varied Hole Transport Layers

AbstractPerovskite solar cells (PSCs) have become a research hotspot both domestically and internationally due to their superior optoelectronic performance as a new type of thin‐film solar cell. One of the methods to enhance the performance of PSCs is the optimization of the hole transport layer(HTL). In this study, COMSOL Multiphysics simulation software is employed to model and simulate PSCs, and perform coupled simulations of the optical, electrical, and thermal properties of PSCs with different HTL. The simulations analyze the carrier concentration, Shockley–Read–Hall (SRH) recombination, electric field profile, and temperature distribution in the devices. The simulation results demonstrate that among the different HTL (CuO, Spiro‐OMeTAD, and NiO), NiO exhibited more favorable characteristics as a HTL for improving the photovoltaic conversion efficiency of PSCs. The photovoltaic conversion efficiency reached 17.14% with NiO as the hole transport layer, and the SRH recombination rate in PSCs based on NiO HTL of PSCs is lower than CuO and Spiro‐OMeTAD, facilitating efficient charge transport. Furthermore, the temperature distribution of PSCs is analyzed based on different HTL, and the results indicate that PSCs with NiO as the hole transport layer exhibited higher thermal stability.

Machine Learning‐Assisted Fabrication of PCBM‐Perovskite Solar Cells with Nanopatterned TiO2 Layer

To unlock the full potential of PSCs, machine learning (ML) was implemented in this research to predict the optimal combination of mesoporous‐titanium dioxide (mp‐TiO2) and weight percentage (wt%) of phenyl‐C61‐butyric acid methyl ester (PCBM), along with the current density (Jsc), open‐circuit voltage (Voc), fill factor (ff), and energy conversion efficiency (ECE). Then, the combination that yielded the highest predicted ECE was selected as a reference to fabricate PCBM‐PSCs with nanopatterned TiO2 layer. Subsequently, the PCBM‐PSCs with nanopatterned TiO2 layers were fabricated and characterized to further understand the effects of nanopatterning depth and wt% of PCBM on PSCs. Experimentally, the highest ECE of 17.338% is achieved at 127 nm nanopatterning depth and 0.10 wt% of PCBM, where the Jsc, Voc, and ff are 22.877 mA cm−2, 0.963 V, and 0.787, respectively. The measured Jsc, Voc, ff, and ECE values show consistencies with the ML prediction. Hence, these findings not only revealed the potential of ML to be used as a preliminary investigation to navigate the research of PSCs but also highlighted that nanopatterning depth has a significant impact on Jsc, and the incorporation of PCBM on perovskite layer influenced the Voc and ff, which further boosted the performance of PSCs.

Pengaruh Ketebalan Lapisan Tipis ZnO terhadap Kinerja Sel Surya Perovskit Fleksibel

Photoelectrode preparation that requires high heating temperatures will hinder the future development of PSCs on flexible plastic substrates. Therefore, ZnO is a viable alternative for flexible PSCs because it can be processed at low temperatures. This research focuses on the influence of ZnO photoelectrode layer thickness on the optical properties and performance of PSCs. The transmittance of ZnO thin films was found to be more than 50% in each sample. In addition, the bandgap obtained ranged from 3.12 to 3.20 eV. The efficiency results are 0.90×10-5% at a thickness of 10 µm, 1.09×10-5% at a thickness of 8 µm, 2.68×10-5% at a thickness of 6 µm, and the best efficiency is 4.31×10-5% at 4 µm thickness. Based on the results of research that has been carried out, reducing the thickness of the ZnO photoelectrode layer can increase the transmittance and efficiency of solar cells so that solar cell performance increases.