Perovskite Silicon Tandem Solar Cells Research Articles

Efficient and stable perovskite-silicon tandem solar cells with copper thiocyanate-embedded perovskite on textured silicon

Efficient and stable perovskite-silicon tandem solar cells with copper thiocyanate-embedded perovskite on textured silicon

The Promise and Challenges of Inverted Perovskite Solar Cells.

Recently, there has been an extensive focus on inverted perovskite solar cells (PSCs) with a p-i-n architecture due to their attractive advantages, such as exceptional stability, high efficiency, low cost, low-temperature processing, and compatibility with tandem architectures, leading to a surge in their development. Single-junction and perovskite-silicon tandem solar cells (TSCs) with an inverted architecture have achieved certified PCEs of 26.15% and 33.9% respectively, showing great promise for commercial applications. To expedite real-world applications, it is crucial to investigate the key challenges for further performance enhancement. We first introduce representative methods, such as composition engineering, additive engineering, solvent engineering, processing engineering, innovation of charge transporting layers, and interface engineering, for fabricating high-efficiency and stable inverted PSCs. We then delve into the reasons behind the excellent stability of inverted PSCs. Subsequently, we review recent advances in TSCs with inverted PSCs, including perovskite-Si TSCs, all-perovskite TSCs, and perovskite-organic TSCs. To achieve final commercial deployment, we present efforts related to scaling up, harvesting indoor light, economic assessment, and reducing environmental impacts. Lastly, we discuss the potential and challenges of inverted PSCs in the future.

Structural and photoelectric properties of hybrid halide perovskites CsxMA1-xMgyPb1-yI3 from first-principles

Lead toxicity and stability are important issues to be addressed in organic/inorganic hybrid perovskite solar cell materials. In this study, the electronic, structural, and optical properties of Cs and Mg co-doped organic/inorganic hybrid perovskites were investigated through first-principles calculations. The synergistic effect of (Cs, Mg) doping improves the lattice stability, reduces the content of elemental lead, thereby reducing environmental pollution, and induces a tunable band gap of 0.96–2.58 eV. Perovskite with a bandgap of 1.5–1.6 eV is an ideal adsorbent for solar cells, while that with a bandgap greater than 1.70 eV can be used for perovskite-silicon tandem solar cells. Co-doping of Cs and Mg compresses the neighboring Pb–I and Mg–I bond and distorts the [PbI6] octahedra. The organic/inorganic hybrid perovskites co-doped with cesium and magnesium significantly increase the light absorption coefficients in the near-ultraviolet and visible regions. The predicted Cs and Mg co-doped halide perovskites with intriguing properties would become a promising candidate for applications in solar cells and optoelectronic devices.

Comprehensive device modeling and a performance analysis of perovskite-silicon tandem solar cells through light management

Currently, researchers are paying much attention to perovskite-silicon tandem solar cells due to their great potential to surpass the Shockley–Queisser limit of single silicon solar cells. In order to improve the performance of perovskite-silicon tandem solar cells, various techniques have been employed, including selecting textured structures or optimizing the film thickness in the top perovskite cells. However, despite these efforts, significant losses due to surface reflection and unbalanced light absorption still exist, and the accurate predictions combining both optical and electric calculations towards obtaining higher power conversion efficiency (PCE) are still lacking. In this study, we integrated optical and electrical numerical simulations to precisely investigate the effectiveness of using a pyramidal perovskite (MAPbI3) nanostructured film as an example in perovskite-silicon tandem solar cells to reduce the reflective losses and balance the current densities. Through our calculations, the PCE of tandem solar cells can be improved from 23.1% (the planar structures without texturing) to 29.3% in the best-performing textured tandem devices (with a period of 300 nm and peak-to-valley height of 300 nm) under the consistently calculated absorbed and EQE spectrum. Direct comparisons between calculated results and experimental data could also reveal the influence ascribed to a detailed factor that hinders the PCE improvement. These findings offer valuable theoretical insights for the advancement and optimization of perovskite-silicon tandem solar cells.

Tailoring perovskite crystallization and interfacial passivation in efficient, fully textured perovskite silicon tandem solar cells

Tailoring perovskite crystallization and interfacial passivation in efficient, fully textured perovskite silicon tandem solar cells

Built-in field manipulation through a perovskite homojunction for efficient monolithic perovskite/silicon tandem solar cells

Perovskite-silicon tandem solar cells offer a solution to exceed the Shockley–Queisser limit of their respective single-junction counterparts and significantly reduce the levelized cost of energy (LCOE) of photovoltaic systems. While thick perovskite film is imperative in this tandem configuration to ensure complete coverage on the textured silicon surface, it gives rise to great challenges for carrier transport and extraction. Herein, we designed a layer of mesoporous Al2O3 at the buried interface to establish a perovskite homojunction and mitigate the inherent adverse electric field in the perovskite film. Results showed that the Al2O3 layer evidently interacted with the organic cations of perovskite materials, effectively suppressing the spontaneous ion migration during crystallization. Thus, it altered the semiconductor type of the perovskite film at the buried interface from n-type to p-type, enabling the formation of perovskite homojunction and rendering it suitable for inverted perovskite solar cells (PSCs) by enhancing the built-in electric field. As a result, an outstanding power conversion efficiency (PCE) of 22.16 % is attained for a single junction 1.67 eV PSCs. Furthermore, we successfully crafted efficient monolithic perovskite/silicon tandem solar cells with this strategy, achieving an impressive PCE of 29.04 %. This study highlighted the critical importance of regulating local ion distribution in perovskite films and enhancing the built-in electric field for tandem configurations, which also provided a fresh perspective on the role of mesoporous Al2O3 in PSCs.

Silicon / Perovskite Tandem Solar Cells with Reverse Bias Stability down to -40V. Unveiling the Role of Electrical and Optical Design.

The reverse bias stability is a key concern for the commercialization and reliability of halide perovskite photovoltaics. Here, the robustness of perovskite-silicon tandem solar cells to reverse bias electrical degradation down to -40V is investigated. The two-terminal tandem configuration, with the perovskite coupled to silicon, can improve the solar cell resistance to severe negative voltages when the tandem device is properly designed. While perovskite cells typically exhibit early reverse bias breakdown voltages, the serial connection with silicon cells with large shunt resistances and high voltage breakdown limits their negative polarization and prevent the passage of large current densities when reverse biased. The importance of careful optical design is illustrated, with bottom-limited conditions required to prevent the perovskite topcell from exploring its own breakdown. This aspect is of great importance in the case of partial shading events when the solar spectrum is richer in the IR components than the standard AM1.5G. Notably, 100% of efficiency retained after polarization at -40V in different stressing conditions is observed. The results presented suggest that standard industrial bypass diode schemes may be compatible with silicon/perovskite tandem photovoltaics and provide new guidelines for the standardization of the stressing protocols.

Exploring the potential of tin-based perovskite-silicon tandem solar cells through numerical analysis: A pathway to sustainable energy innovation

“Necessity is the mother of invention.” The global imperative to transition from fossil fuels to renewable energy sources, driven by the pressing issue of climate change, highlights the significance of advancing solar energy technologies. While single junction solar cells have reached a peak efficiency of approximately 31 %, the pursuit of higher efficiency has led to the exploration of tandem solar cell architectures, including perovskite-silicon and all-perovskite configurations. However, the widespread use of lead in perovskite structures raises environmental and health concerns. In response to these challenges, this study proposes a novel approach by integrating a tin-based wide bandgap absorber layer with a silicon HIT solar cell (Heterojunction with Intrinsic Layer). The investigation consists of an extensive exploration of six different carrier transport layers (CTL) for the top perovskite layer, considering variations in thickness and defect density. A comprehensive analysis of charge carrier dynamics within the device is conducted to understand the role of defect density in influencing solar cell performance parameters. Simulation results show that the overall tandem device gives an encouraging PCE of 32.12 % in 2 T configuration due to its excellent high value of current density matching 17.63 mA/cm2 and open-circuit voltage of 2.19V. We sincerely hope that our work will open new avenues in the field of Solar Photovoltaics paving the way for future innovations.

Machine Learning-Enabled Optical Architecture Design of Perovskite Solar Cells.

Perovskite solar cells, emerging as a cutting-edge solar energy technology, have demonstrated a power conversion efficiency (PCE) of >26%, which is below the theoretical limit of 33%. This study, employing a combination of neural network models and high-throughput simulation calculations, taking the single-junction FAPbI3 cell as an illustrative example, indicates that a pyramid structure, in comparison of a planar one, can increase the highest Jsc to 27.4 mA/cm2 and the PCE to 28.4%. Both Jsc and PCE surpass the currently reported experimental results. The optimized periodicity and tilt angle of the pyramid structure align with the textured structure of crystalline silicon solar cells. These results underscore the substantial development potential of neural network inverse design based on high-throughput calculations in the field of optoelectronic devices and provide theoretical guidance for the design of monolithic perovskite-silicon tandem solar cells.

Enhancing perovskite-silicon tandem solar cells through numerical optical and electric optimizations for light management.

We integrated optical and electrical numerical simulations to precisely investigate the effectiveness of using a pyramidal perovskite (Cs0.18FA0.82Pb(I,Br)3) nanostructured film as an example in perovskite-silicon tandem solar cells to reduce reflective losses and balance the current densities. Through our calculations, the PCE of tandem solar cells can be improved from 29.2% (the planar structures without texturing) to 36.1% in the best-performing textured tandem devices under the consistently calculated absorbed and EQE spectrum, where the predicted open-circuit voltage could reach over 2 V. These findings offer valuable theoretical insights for the advancement and optimization of perovskite-silicon tandem solar cells.

Investigation of perovskite layer growth from solution on textured substrates

Surface textures are indispensable to minimize optical losses in perovskite-based solar cells. However, the solution-processing of perovskite layers is often not compatible with textured substrates, and little is known about the film growth thereon. This study aims to elucidate the growth process of perovskite layers from solution on textured substrates and to identify the texture features ensuring compatibility with perovskite solution-processing. Using nanoimprint-lithography we prepared three different periodically as well as randomly textured glass substrates for spin-coated perovskite solar cells, of which one was duplicated from a commercially available texture. During the perovskite crystallization process, a time-resolved in situ photoluminescence measurement was conducted. The photoluminescence signal was not found to substantially alter using textured substrates with texture heights around 500 nm. Optical absorptance spectroscopy and scanning electron microscopic imaging were applied to investigate the growth, crystal structure, and optical properties of solution-processed perovskite on top of different textures. We find that periodic textures with height around 500 nm enable homogeneous solution-processed perovskite layers with optimized optical performance. In contrast, texture heights of several micrometers lead to macroscopic holes in the perovskite film. The results of this study will help to find optimum optical textures for high-efficiency perovskite single-junction and perovskite-silicon tandem solar cells.

Scenario-based recycling strategies for perovskite-silicon tandem solar cells: a harmonized life cycle assessment study

Environmental performances of end-of-life strategies for perovskite–silicon tandem solar cells.

Toward efficient and industrially compatible fully textured perovskite silicon tandem solar cells: Controlled process parameters for reliable perovskite formation

AbstractCapitalizing on the existing silicon industry, fully textured perovskite‐silicon tandem solar cells have a great potential to penetrate the electricity market. While the use of textured silicon with large pyramid size (> 1 μm) enhances the power conversion efficiency (PCE), it also presents process complications. To achieve high performance, meticulous control of deposition parameters on textured silicon is required. This study provides a guideline for the use of the hybrid evaporation/spin‐coating route to form high‐quality perovskite absorbers. Using various characterization techniques, we highlight intrinsic differences between perovskite growth on flat versus textured substrates. Furthermore, we provide pathways to ensure a high perovskite phase purity, reveal mitigation strategies to avoid the formation of undesired dendritic perovskite structures, give guidelines to ensure photostability, and discuss the “misleading” effect of residual PbI2 on the perovskite photoluminescence response. A good understanding of the perovskite growth on textured silicon enables the fabrication of a tandem device with a PCE > 26% (without employing additives or surface treatments) and a good operational stability. The comprehensive guidelines in this study provide a better understanding of perovskite formation on textured silicon and can be transferred when upscaling the hybrid route perovskite deposition.

Nanostructured anti-reflection coating for absorption enhancement in perovskite silicon tandem solar cells

Perovskite-silicon tandem solar cells have captured the attention of the solar cell research community due to the advantages of perovskites, such as, an easy fabrication process using sol-gel methods and silicon bottom cells that can be fabricated using well-established fabrication techniques. The present study discusses the design, optimization, and numerical analysis related to the role of nanostructured anti-reflection coating design for perovskite (MAPbI3) silicon tandem solar cells. In the design, the top cell is taken as MAPbI3 and the bottom cell is C-silicon. The anti-reflection coating is designed with SiO2 nanoparticles embedded in ITO. These nanostructured top anti-reflection coating results are compared with its planar top cell counterpart. SiO2 nanoparticle diameter and interparticle separation are optimized to get maximum absorption in the top cell. Upon optimization, it was found that a design having SiO2 nanoparticles with a diameter of 60 nm and no interparticle separation showed the most reduction in reflection, which in turn led to an increase in absorption in the top cell. The proposed structure enhances current density by 8.3% over the planar cell. This top cell current is matched to the bottom silicon thickness. These findings were validated using Mie scattering and the Bruggmann effective medium approximation.

Co-evaporated oriented DMA1-xCsxPbI3 perovskite films for photovoltaics

Thermally evaporated cesium lead triiodide (CsPbI3) is a frontier research direction for perovskite-silicon tandem solar cells because of the matching bandgap and good conformality with textured silicon. However, the random orientation and small grains for the co-evaporated CsPbI3 thin films fabricated at low temperature, resulting in harmful defects and non-radiative recombination. Here, dimethylammonium iodide (DMAI) is introduced into the co-evaporation system at a substrate temperature of 50 °C to prepare preferentially oriented DMA0.06Cs0.94PbI3 film with less defects and enhanced humidity stability. The bandgap also can be reduced from 1.76 eV (γ-CsPbI3) to 1.73 eV. The p-i-n photovoltaic device based on this film achieves an efficiency of 16.10% with suppressed non-radiative recombination, rivaling with the thermally evaporated wide-bandgap CsPbI3 solar cells prepared at a high temperature (∼ 350 °C). This in-situ evaporated alloying strategy can pave the way for the crystallization and defect control during perovskite co-evaporation.

Analysis of nanostructured anti reflection coating for various perovskite layer thicknesses in perovskite silicon tandem solar cells

The anti-reflection coating (ARC) plays an important role in the design of every kind of solar cell. The suitable optimization of the ARC layer can make a lot of difference in the final output of the cell, by reducing the reflections at the surface. In this regard, the present paper highlights and analyses numerically the effect of nanostructured ARC for different top perovskite layer thicknesses in perovskite-silicon tandem solar cells. In the present case, the nanostructures for ARC are considered to be made up of SiO2 nanoparticles (NP) embedded in ITO. To evaluate the effect of nanostructure for this proposed cell, the nanostructured tandem cell is compared with its planar ARC-based reference cell. The top perovskite active thickness is varied from 100 nm to 800 nm. It has been found that the effect of nanostructured ARC is more pronounced for thinner perovskite layer-based cells than for thicker layers. To reduce reflections at the front surface, the SiO2 NP diameter and inter-particle spacing are optimized. With the nanostructured ARC at the top, the cell achieved the current density rise of 11.3% as compared to the reference cell for a 100 nm thick perovskite-based tandem cell design. As both the sub-cells are in series in tandem design, the top cell current is matched to the bottom silicon layer current by optimizing the bottom cell too. The proposed ARC design has the added advantage that it can simply be done with sol–gel processes.

Versatile implied open‐circuit voltage imaging method and its application in monolithic tandem solar cells

AbstractAs the efficiency of perovskite silicon tandem solar cells is increasing, the upscaling for industrial production is coming into focus. Spatially resolved, quantitative, fast, and reliable contactless measurement techniques are demanded for quality assurance and to pinpoint the cause of performance losses in perovskite silicon tandem solar cells. In this publication, we present a measurement method based on spectrally integrated photoluminescence (PL) imaging to extract subcell‐selective implied open‐circuit ( ) images from monolithic perovskite silicon tandem solar cells. We validate the approach using spectrally resolved absolute PL measurements based on an integrating sphere for the perovskite top cell and PL‐calibrated carrier lifetime images for the silicon bottom cell. Additionally, measurements of solar cells with low contact losses are used to validate the new measurement technique. We find a good agreement of the images with the validating measurements with a maximum deviation of well below 1% compared to the validation measurements.

Perovskite/silicon tandem solar cells-compositions for improved stability and power conversion efficiency.

Perovskite/Silicon Tandem Solar Cells (PSTSCs) represent an emerging opportunity to compete with industry-standard single junction crystalline silicon (c-Si) solar cells. The maximum power conversion efficiency (PCE) of single junction cells is set by the Shockley-Queisser (SQ) limit (33.7%). However, tandem cells can expand this value to ~ 45% by utilising two stacked solar cells to harvest the solar spectrum more efficiently. 33.9% PCE has already been achieved with PSTSCs. This perspective analyses recent advances in PSTSC technology, with an emphasis on optimal perovskite composition, the problem and mitigation of light-induced halide phase segregation, self-assembled hole transporting monolayers and additives that can improve and stabilise the perovskite. Top-performing compositions show three cationic components (Cs+, FA+, Pb2+) and three anionic (I-, Br-, Cl-) with a bandgap between 1.55 and 1.77eV and a theoretical maximum of 1.73eV (717nm). Anionic additives such as (Br3)- and SCN- reduce trap states and segregation. 2D-perovskite grain boundary interfaces are created with cationic alkylammonium additives such as methyl-phenethylammonium (MPEA) and result in improved performance. 2-, 3- or 4-terminal devices with a (partly) textured silicon heterojunction (SHJ) bottom cell are ideal. An ultra-thin interfacial recombination layer (~ 5nm) of indium tin oxide (ITO) or indium zinc oxide (IZO) containing a carbazole-based hole transporting self-assembled monolayer (Me-4PACz) is used for optimal 2-terminal tandem devices.

Loss Analysis of Fully‐Textured Perovskite Silicon Tandem Solar Cells: Characterization Methods and Simulation toward the Practical Efficiency Potential

Optimally enhancing the performance of perovskite silicon tandem solar cells comes with accurate identification of loss origins in the device in combination with optoelectrical device simulations assessing the respective efficiency gains to prioritize optimization pathways. Herein, various characterization methods, namely, spectrally resolved photoluminescence (PL), transient‐PL, PL‐based implied open‐circuit voltage (iVOC) imaging, spectrometric characterization, and Suns‐VOC measurements are combined to quantify current density–voltage (jV) photovoltaic metric losses of a fully‐textured perovskite silicon tandem solar cell (26.7% efficiency). The extracted device characteristic parameters are then used as a reference for the comprehensive optoelectrical Sentaurus simulation model which precisely reproduces the experimentally obtained optical and electrical solar cell characteristics, considering mobile ion dynamics. Subsequently, starting from the current device design, the authors alleviate one step at a time the loss constraints and show the impact of each loss channel on the efficiency, identifying the three major ones to be at the: 1) perovskite/C60 interface (−4.6%abs) , 2) the series resistance (−2.9%abs), and 3) light management (−2.1%abs), which limit the VOC, fill factor, and jSC of the device, respectively. Furthermore, it is demonstrated that a practical efficiency potential of 39.5% can be regarded as a practical limit for the presented tandem device architecture.

Molecular engineering of hole-selective layer for high band gap perovskites for highly efficient and stable perovskite-silicon tandem solar cells

Molecular engineering of hole-selective layer for high band gap perovskites for highly efficient and stable perovskite-silicon tandem solar cells