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•Ionic liquids (ILs) aided-device engineering champions is widely reviewed.•The role of ILs in the production of high-quality perovskite film is discussed.•ILs can potentially improve ...the long-term stability of perovskite solar cells.•ILs represents a significant step toward reliable perovskite PV technology.
The efficiency of perovskite solar cells (PSCs) is rapidly increasing, so that their long-term operational stability has become a major focus for commercialization and market adoption. The development of novel strategies and materials to improve the stability of small and large solar modules without compromising power conversion efficiency (PCE) is an ongoing challenge. Ionic liquids (ILs) are emerging as useful additives, solvents, and charge transport materials for the preparation of highly efficient perovskite films. Perovskite crystallizes slowly in ILs to form large and uniform grains, and PSCs fabricated with high-quality perovskite films are efficient and stable. Herein we review recently developed systemic device engineering, and we discuss the impact of ILs in the production of highly efficient and stable PSCs. This review is intended to serve as a guide to develop highly crystalline perovskite films with larger grains and more homogeneous morphologies, all of which contribute to enhancing the stability of PSC performance. Recent progress in the use of ILs as solvents and additives for PSCs is a significant step toward developing reliable perovskite photovoltaic devices. Finally, we discuss challenges and future research directions for the fabrication of efficient and stable PSCs.
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•Low temperature processed high-quality TiO2 nanoparticles film were prepared.•TiO2 layer was optimized while fabricating efficient perovskite solar cells.•3D opto-electrical ...simulations investigate optical and electrical properties of the device.•Efficient nanophotonic front contact is designed for efficient perovskite solar cells.•Optimized device enhances ECE by 25 ~ 30%, up to 23%, compared to the flat contact device.
We report on the preparation and optimization of low temperature (<200 °C) processed TiO2 film as an electron transport layer (ETL) for high-performance perovskite solar cells (PSCs) compatible with flexible substrates. A high-quality ETL is spin-coated from hydrothermal synthesized single-phase crystalline anatase TiO2 nanoparticles (NPs) with an average diameter of 6 ~ 10 nm. The surface of the high crystallite TiO2 NPs reveals a tendency toward interparticle necking, facilitating compact scaffolds, resulting in PSCs with high power conversion efficiencies (PCEs). The influence of low and high temperature treated TiO2 ETL on the device performance is studied. The best planar device fabricated in superstrate configuration (sup-C) exhibits a PCE of 17.1% with a JSC of 20.3 mA/cm2. The PCE can be increased by ~ 25%, up to 23%, by moving from planar architecture in sup-C to the textured solar cell in substrate configuration (sub-C). The PSC covered with a nanophotonic-structured front contact allows gaining 8% and 15% on VOC and JSC, respectively, where 2/3 of JSC gain is attributed to improved light incoupling, while the remaining 1/3 is due to increased diffraction at long wavelengths. The optical and electrical characteristics of the devices are investigated by 3D finite-domain time-domain (FDTD) and finite element method (FEM) rigorous simulations. Detailed guidelines on the nanophotonic design are provided.
Perovskite solar cells (PSCs) have appeared as a promising design for next-generation thin-film photovoltaics because of their cost-efficient fabrication processes and excellent optoelectronic ...properties. However, PSCs containing a metal oxide compact layer (CL) suffer from poor long-term stability and performance. The quality of the underlying substrate strongly influences the growth of the perovskite layer. In turn, the perovskite film quality directly affects the efficiency and stability of the resultant PSCs. Thus, substrate modification with metal oxide CLs to produce highly efficient and stable PSCs has drawn attention. In this review, metal oxide-based electron transport layers (ETLs) used in PSCs and their systemic modification are reviewed. The roles of ETLs in the design and fabrication of efficient and stable PSCs are also discussed. This review will guide the further development of perovskite films with larger grains, higher crystallinity, and more homogeneous morphology, which correlate to higher stable PSC performance. The challenges and future research directions for PSCs containing compact ETLs are also described with the goal of improving their sustainability to reach new heights of clean energy production.
With the rapid improvement of perovskite solar cells (PSCs), long-life operational stability has become a major requirement for their commercialization. In this work, we devised a pristine ...cesium–formamidinium–methylammonium (termed as CsFAMA) triple-cation-based perovskite precursor solution into the ionic liquid (IL)-assisted MAPbI3 nanoparticles (NPs) through a seeded growth approach in which the host IL-assisted MAPbI3 NPs remarkably promote high-quality perovskite films with large single-crystal domains, enhancing the device performance and stability. The power conversion efficiency (PCE) of the MAPbI3 NP-seeded growth of MAPbI3 NPs/CsFAMA-based PSCs is as high as 19.44%, which is superior to those of MAPbI3 NPs and pristine CsFAMA films as the photoactive layer (9.52 and 17.33%, respectively). The long-term light-soaking and moisture stability of IL-aided MAPbI3 NPs/CsFAMA-based devices (non-encapsulated) remain above 90 and 80%, respectively, of their initial output after 2 h of light illumination (1 sun) and 6000 h storage at ambient with a relative humidity range of 30–40%. The use of the IL-assisted MAPbI3 NP-seeded growth for PSCs is a significant step toward developing stable and reliable perovskite photovoltaic devices.
Titanium dioxide (TiO2) based planar perovskite solar cells (PSCs) suffer from poor long-term stability and show hysteretic behaviour in the device characteristic curve. In addition to the ...exceptional bulk properties of the perovskite, the performance and stability are also highly dependent on the conduction band energy, conductivity, and electronic trap states of the TiO2 compact layer (CL). In this work, single-phase brookite (BK) TiO2 nanoparticles (NPs), synthesized via a hydrothermal method using a water-soluble titanium complex, are incorporated as a bridge between the perovskite and TiO2 CL. This resulted in uniform large perovskite grain growth with enhanced crystallinity, significant reduction in trap/defect sites and interfacial recombination as revealed by scanning electron microscopy (SEM), photoluminescence (PL), and impedance spectroscopy results, respectively. The resulting PSCs show highly reproducible power conversion efficiencies (PCEs) up to ∼18.2% (vs. ∼15%) with a stable performance of 18% under continuous light illumination (1 sun) at the maximum power point tracking (MPPT) in contrast to only TiO2 CL based planar devices. To the best of our knowledge, this is so far the best photo-stability data reported for brookite NP based PSCs. Based on our present study, at the end we provide further direction to enhance the stability of planar PSCs.
Organic solar cells (OSCs) have attracted great interest in recent years owing to such features as low cost, light weight, and flexibility. The top electrodes of OSCs are generally fabricated by ...vapor deposition on organic layers. Recently, electrode lamination has emerged as a cost-effective process for the fabrication of top electrodes of OSCs because it does not damage organic thin layers. However, problems abound, including the low short-circuit current density (JSC) and the poor device durability of the resulting OSCs, which are due to the weak contact between the laminated electrode films and the organic layers. Herein we report an electrode sticker that can be firmly attached to an organic layer by thermocompression to realize electrode sticker-laminated OSCs with good JSC and device durability. The electrode sticker-laminated OSCs showed high JSC that approached that of electrode-sublimated OSCs, and their PCE values remained unchanged and were 98% of the maximum value after continuous photo-irradiation for 100 h under ambient conditions. The electrode sticker can be used to fabricate low-cost OSCs with good performance and durability for practical applications.
•“Electrode sticker” was developed for preparing durable electrode-laminated OSCs.•The electrode-laminated OSCs showed similar JSC to that of electrode-sublimated OSCs.•PCE of the electrode-laminated OSCs almost unchanged after 100 h of photo-irradiation.
The insufficient stability of CH3NH3PbI3 (MAPbI3)-based perovskite solar cells (PSCs) remains a significant concern in this field of research, so a device engineering approach is required to obtain ...efficient, stable PSCs. The present work used a sequential deposition process to alternately fabricate thin MAPbI3-based perovskite and cesium iodide (CsI) layers with precise control over the CsI intercalation, producing high quality cesium containing perovskite films. The optimal CsI film thickness when applied to either the up, down or both layers of the MAPbI3 perovskite film was also assessed. Interestingly, the application of a double layer CsI layer greatly altered the perovskite morphology to produce large grain sizes, as a result of the precise intercalation of the CsI molecules into the host MAPbI3. Furthermore, PSCs made with double layer CsI intercalation exhibited power conversion efficiencies as high as 18.43%. These exceeded the values obtained from devices made with pristine MAPbI3, or with CsI intercalation on either the bottom or top of the perovskite (16.14%, 17.92% and 17.26%, respectively). A double layer CsI intercalation device was stored in the dark at relative humidities of 40–50% for more than 4000 h and retained over 83% of its initial efficiency.
Sequential deposition technique was used to alternately fabricate CH3NH3PbI3 (MAPbI3) and cesium iodide (CsI) thin layers with precise control over the CsI intercalation, producing large grain size, and high-quality cesium containing perovskite films. When the CsI double-layer intercalate into the MAPbI3 framework effectively improves the efficiency and long-term stability of the perovskite solar cells. Display omitted
•Double layer CsI intercalation greatly altered the perovskite morphology.•The optimal CsI film thickness when applied to either the up, down or double layers of the MAPbI3 film were assessed.•Double layer CsI intercalation significantly improve the long-term stability of perovskite solar cells.
With the rapid improvement of perovskite solar cells (PSCs), long-life operational stability has become a major requirement for their commercialization. In this work, we devised a pristine ...cesium-formamidinium-methylammonium (termed as CsFAMA) triple-cation-based perovskite precursor solution into the ionic liquid (IL)-assisted MAPbI
nanoparticles (NPs) through a seeded growth approach in which the host IL-assisted MAPbI
NPs remarkably promote high-quality perovskite films with large single-crystal domains, enhancing the device performance and stability. The power conversion efficiency (PCE) of the MAPbI
NP-seeded growth of MAPbI
NPs/CsFAMA-based PSCs is as high as 19.44%, which is superior to those of MAPbI
NPs and pristine CsFAMA films as the photoactive layer (9.52 and 17.33%, respectively). The long-term light-soaking and moisture stability of IL-aided MAPbI
NPs/CsFAMA-based devices (non-encapsulated) remain above 90 and 80%, respectively, of their initial output after 2 h of light illumination (1 sun) and 6000 h storage at ambient with a relative humidity range of 30-40%. The use of the IL-assisted MAPbI
NP-seeded growth for PSCs is a significant step toward developing stable and reliable perovskite photovoltaic devices.
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