Perovskite Tandem Solar Cells Research Articles

Integrated 4-Terminal All-Inorganic Perovskite Tandem Solar Cell with Open-Circuit Voltage Exceeding 2.1 V for Water Splitting

This work reports on Sn-Pb binary metal inorganic perovskites as narrow-bandgap absorbers for integrated 4-terminal all-inorganic perovskite tandem solar cells (TSCs). A series of Sn-Pb binary metal CsPb1–xSnxI3-yBry inorganic perovskites with tunable bandgaps ranging from 1.28 to 1.45 eV were synthesized through tuning the Sn-Pb and I-Br contents. The TSC device using a narrow-bandgap CsPb0.5Sn0.5I2.7Br0.3 bottom cell with a wide-bandgap semi-transparent CsPbI1.5Br1.5 top cell achieved a remarkable power conversion efficiency over 18% and a high open-circuit voltage (VOC) of 2.13 V, a very attractive feature for solar fuel production. To the best of our knowledge, this is the first trial of TSCs entirely made of all-inorganic perovskite absorbers, and also the record VOC achieved among double-junction TSCs based on integration of narrow- and wide-bandgap perovskite absorbers so far. Using this novel all-inorganic perovskite TSC in conjunction with a water-splitting system employing Pt/C for hydrogen evolution reaction and Fe/Ni foam for oxygen evolution reaction in alkaline electrolyte, we achieved an unprecedented solar-to-hydrogen efficiency over 13% under standard illumination test conditions.

Additive Engineering for High‐Performance Two‐Dimensional Dion–Jacobson Pb–Sn Alloyed Perovskite Solar Cells

Two‐dimensional perovskite materials attract great attentions for the application of perovskite solar cells (PSCs) due to the regulable bandgap and high stability. However, the power conversion efficiency (PCE) of 2D PSCs is far behind in that of three‐dimensional PSCs. Herein, Dion–Jacobson (DJ) phase Pb–Sn perovskite of (PhDMA)MA4(Pb0.5Sn0.5)5I16 in 2D PSCs is introduced, which has suitable bandgap of 1.27 eV and offers the candidate for the absorber of bottom device in all perovskite tandem solar cells. The nonlinear bandgap behavior of 2D Pb–Sn perovskite materials is certified by adjusting the recipe of precursors to vary the bandgap of perovskite films. Moreover, MACl is employed to improve the film quality of 2D Pb–Sn perovskite, leading to the suppression of the defect density and nonradiative recombination for 2D PSCs. As a result, a high PCE of 12.2% is achieved for DJ phase 2D Pb–Sn PSCs.

All-inorganic CsPb1-xSnxI2Br perovskites mediated by dicyandiamide additive for efficient 4-terminal tandem solar cell

Sn-Pb mixed perovskite solar cells (PSCs) have attracted research attention due to their application in tandem solar cells, but suffered from pin-hole morphology and device instability. In this work, dicyandiamide (DCD) is used as an antioxidative additive to regulate the crystallization and passivation of all-inorganic CsPb1-xSnxI2Br film. The strong coordination bonding between DCD and Pb/Sn not only effectively eliminates the pin-holes but also inhibits the oxidation of Sn2+ at low temperature. The power conversion efficiency (PCE) of inverted PSC (ITO/NiOx/CsPb0.6Sn0.4I2Br:DCD/ZnO/PC61BM/Ag) is improved from 10.53% to 14.17% (0.1 cm2), which is also one of the highest efficiencies of all-inorganic Sn-Pb mixed PSC. Meanwhile, compare with the control devices, the target device exhibits better stability after a series of tests. In addition, combining semitransparent 1.92-eV-bandgap top PSC (ITO/NiOx/CsPbI2Br:DCD/Ti0.9Sn0.1O2/IZO/MgF2) with CsPb0.6Sn0.4I2Br:DCD (1.54 eV) bottom PSC, an efficiency of 19.61% is demonstrated in all-inorganic 4-terminal (4T) tandem PSC. This work paves the way towards efficient all-inorganic perovskite tandem solar cells.

Device Modeling and Optimization for an Efficient Two-Terminal Perovskite Tandem Solar Cell

Device Modeling and Optimization for an Efficient Two-Terminal Perovskite Tandem Solar Cell

Design perspective and numerical analysis of all perovskite 2-terminal and 4-terminal tandem solar cell

All perovskite multi-junction device represents a feasible path toward power conversion efficiency (PCE) of >35% and has the potential to conquer the schokley quiesser limit of a single junction device. In this study, we have investigated all perovskite tandem solar cell in 2-terminal and 4-terminal device architecture. An unprecedented device architecture was employed, having a large bandgap perovskite, i.e. MA0.9Cs0.1Pb(I0.6Br0.4)3, as a top sub-cell active layer and a narrow bandgap perovskite, i.e. FA0.8MA0.2Sn0.5Pb0.5I3 as a bottom sub-cell active layer. A rigorous device validation was done to confirm the self-consistency of the model. The effect of thickness on the subcells in the standalone condition was first studied to report the best performing standalone subcells. Next, the performance of the 2-terminal tandem device was investigated, and a current matching condition was found to register the best performing device. Finally, a rigorous performance analysis of the 4-terminal device was done to compare its performance with the 2-terminal device. We obtained a remarkable PCE of 22.24% and 33.46% for 2-terminal and 4-terminal devices by optimizing all the parameters, respectively.

Investigation of optical and electrical properties of novel 4T all perovskite tandem solar cell

In this paper, a combined three-dimensional (3D) optical-electrical simulation of non-pb and flexible four-terminal (4T) all perovskite tandem solar cell (APTSC) is presented. In this structure, polyethylene terephthalate (PET) is used as substrates, while the top sub cell has a MAGeI_{3} absorber layer and the bottom sub cell has a MASnI_{3} absorber layer. This structure is used as a reference in this paper and the optical and electrical properties of it are investigated using the finite element method (FEM). It is shown that this structure has a total power conversion efficiency (PCE) of 24.65%. Then, the elimination of the buffer layer and the addition of antireflection layer (ARL) strategies, as well as the use of periodic nano-texture patterns, are used to increase the reference structure’s total PCE. A free-buffer layer tandem device is presented to minimize the parasitic absorption. While the total PCE is improved by 1.14% in this case, one of the fabrication steps is also eliminated. A plasma-polymer-fluorocarbon (PPFC) coating layer is suggested as ARL on the substrates of both sub cells to reduce reflection loss. With optimized these layers thickness, total PCE is increased by 12.76%. Because the PPFC layer is hydrophobic, the top surface of two sub cells in this structure has self-cleaning characteristic. As a result, this device offers long-term moisture resistance. Finally, the best structure in terms of the maximum total PCE is presented by increasing optical path-length utilizing nano-photonic and nano-plasmonic structures. The final structure is offered as a 4T tandem solar cell (TSC) that is environmentally friendly, extremely flexible, and has self-cleaning capability, with a total PCE of 30.14%, which is greater than the total PCE of the reference structure by 22.27%.

Antiperovskite materials as promising candidates for efficient tandem photovoltaics: First-principles investigation

In the past few years, the perovskite tandem solar cells show commendable developments in achieving the power conversion efficiency of 30% which is relatively higher than that produced by the single -junction solar cells. But, to the best of our knowledge, there is no literature available regarding the antiperovskite based tandem solar cells. This is the first study reporting the applicability of some predicted antiperovskite compounds Mg3PN, Ca3PN, Sr3PN, Ba3PN, BaSr2PN, Ba1.5Sr1.5 PN, and Ba2SrPN with suitable properties for using as the best absorbing layers in higher efficient tandem solar cell. These seven antiperovskite compounds attain direct band gap nature with band gap values ranging from 1.1 eV to 2.3 eV. The absorption coefficient, optical conductivity and extinction coefficients are found relatively higher in the visible region. Besides, low reflectivity is also analysed in the visible region for the compounds. Low charge carrier effective masses and low recombination rate between the charge carriers can also be observed in the seven materials and thus boost up the carrier mobility and electrical conductivity. Besides, the excitonic binding energy values are also found to be very small for all the predicted compounds. Since all the compounds stabilize in the same crystal structure, the lattice mismatch between each cell will become so less which in turn will be beneficial for making the tandem solar cell. So, it is more suitable to use these materials as the absorbing layers in tandem solar cells apart from use them in single junction photovoltaics since the power conversion efficiency will be more for multijunction/tandem solar cells.

Highly Efficient and Reliable Semitransparent Perovskite Solar Cells via Top Electrode Engineering

AbstractTransparent electrodes are essential to allow optical transparency for realizing semitransparent perovskite solar cells (ST‐PSCs). This study addresses gallium‐ and titanium‐doped indium oxide (IO:GT) between the electron transport layer (ETL) and top electrode to potentially replace conventional indium tin oxide (ITO) used in inverted ST‐PSCs. The shallower work function (−4.23 eV) of IO:GT than that (−4.69 eV) of conventional ITO contributes to suppressing the formation of the Schottky barrier and enhancing the charge transport at the ETL/cathode interface. By adopting IO:GT, the ST‐PSC exhibits an enhancement in power conversion efficiency (PCE) from 8.59% to 17.90% (certified 17.53%) with an average visible transmittance (AVT) of 21.9%, which is the record PCE at similar AVT among all ST‐PSCs reported to date. Moreover, combining these ST‐PSCs as the top cell, a four‐terminal perovskite–perovskite tandem solar cell is realized, showing a high PCE of 23.35%. Furthermore, the stability of the ST‐PSCs is confirmed excellent, maintaining over 96% of the initial PCE after 1864 h (≈77 days) in air ambient without encapsulation, which is better than the device employing a metal cathode. Therefore, these results demonstrate that the adoption of IO:GT can be a promising route for efficient and stable inverted ST‐PSCs with preferred transparency.

Detecting the Knowledge Domains of Compound Semiconductors.

The development of compound semiconductors (CS) has received extensive attention worldwide. This study aimed to detect and visualize CS knowledge domains for quantifying CS research patterns and emerging trends through a scientometric review based on the literature between 2011 and 2020 by using CiteSpace. The combined dataset of 24,622 bibliographic records were collected through topic searches and citation expansion to ensure adequate coverage of the field. While research in “solar cell” and “perovskite tandem” appears to be the two most distinctive knowledge domains in the CS field, research related to thermoelectric materials has grown at a respectable pace. Most notably, the deep connections between “thermoelectric material” and “III-Sb nanowire (NW)” research have been demonstrated. A rapid adaptation of black phosphorus (BP) field-effect transistors (FETs) and gallium nitride (GaN) transistors in the CS field is also apparent. Innovative strategies have focused on the opto-electronics with engineered functionalities, the design, synthesis and fabrication of perovskite tandem solar cells, the growing techniques of Sb-based III–V NWs, and the thermal conductivity of boron arsenide (BAs). This study revealed how the development trends and research areas in the CS field advance over time, which greatly help us to realize its knowledge domains.

Gradient Doping in Sn-Pb Perovskites by Barium Ions for Efficient Single-Junction and Tandem Solar Cells.

Narrow-bandgap (NBG) tin (Sn)-lead (Pb) perovskites generally have a high density of unintentional p-type self-doping, which reduces the charge-carrier lifetimes, diffusion lengths, and device efficiencies. Here, ap-nhomojunction across the Sn-Pb perovskite is demonstrated, which results from a gradient doping by barium ions (Ba2+ ). It is reported that 0.1mol% Ba2+ can effectively compensate the p-doping of Sn-Pb perovskites or even turns it to n-type without changing its bandgap. Ba2+ cations are found to stay at the interstitial sites and work as shallow electron donor. In addition, Ba2+ cations show a unique heterogeneous distribution in perovskite film. Most of the barium ions stay in the top 600nm region of the perovskite films and turn it into weakly n-type, while the bottom portion of the film remains as p-type. The gradient doping forms a homojunction from top to bottom of the perovskite films with a built-in field that facilitates extraction of photogenerated carriers, resulting in an increased carrier extraction length. This strategy enhances the efficiency of Sn-Pb perovskite single-junction solar cells to over 21.0% and boosts the efficiencies of monolithic perovskite-perovskite tandem solar cells to 25.3% and 24.1%, for active areas of 5.9mm2 and 0.94cm2 , respectively.

Design and optimization of highly efficient perovskite/homojunction SnS tandem solar cells using SCAPS-1D

Double-junction tandem solar cells containing a wide-bandgap top cell and a narrow-bandgap bottom cell have a great potential to outperform current single-junction photovoltaic technologies. However, careful consideration is required in the selection and optimization of both sub-cells to obtain full benefit. In this study, we present numerical simulations of tandem solar cells with tin sulfide (SnS) bottom sub-cells and organic–inorganic lead halide perovskite top sub-cells using SCAPS-1D. The performance of SnS homojunction solar cell optimized by investigation of the p-type and n-type layer thicknesses, doping concentrations, defect densities, and interface defects. Afterward, the perovskite solar cell is optimized in terms of variation in absorber bandgap (1.55–1.75 eV) and thickness (100–800 nm). To properly simulate tandem devices, bottom cells are optically filtered by calculated spectra of perovskite solar cells. Current matching has been done by varying thickness of the perovskite sub-cell with different bandgaps, and the optimized 28.92% efficiency has been revealed for the perovskite/SnS tandem device. This is the first numerical simulation using homojunction SnS as a bottom sub-cell in perovskite tandem solar cells to the best of our knowledge. Results suggest that tin sulfide homojunction solar cells could be a low-cost and environmentally friendly bottom sub-cell for efficient perovskite tandem solar cells.

Improved performance study of monolithic all perovskite tandem solar cell in nip and pin structure

All perovskite tandem solar cell (APTSC) is among the most efficacious approach for fabricating high performance solar cell. In this paper, we have comparatively studied APTSC in nip and pin configuration. Performance of APTSC with FA0.8Cs0.2Pb(I0.7Br0.3)3 and (FASnI3)0.6(MAPbI3)0.4:Cl perovskite was simulated and improved by varying electron and hole transport layer for best output. Both the configuration was simulated and optimized on SCAPS-1D modelling software for best performance output. The device in pin configuration outperformed with PCE of 32.3 %, when compared with the device in nip configuration with the PCE of 31.82 %. This performance could be primarily attributed to the band alignment and number of layers in the device structure. All the photovoltaic parameters except fill factor was low in case of pin configuration. The work provides insight in understanding the device fabrication process in both the cases. This study would help us to understand and analyze the role of device configuration in photovoltaic cell.

A Low-Cost Hole Transport Layer Enables Cspbi2br Single-Junction and Tandem Perovskite Solar Cells with Record Efficiencies of 17.8% and 21.4%

A Low-Cost Hole Transport Layer Enables Cspbi2br Single-Junction and Tandem Perovskite Solar Cells with Record Efficiencies of 17.8% and 21.4%

Impact of lifetime on the levelized cost of electricity from perovskite single junction and tandem solar cells

The calculated levelized cost of electricity for single junction and tandem devices show that when the time for perovskite devices to degrade to 85% of the original output (T85) is only 3 years, tandem device are economically favorable.

Recent progress and future prospects of perovskite tandem solar cells

Organic–inorganic metal halide perovskite solar cells represent the fastest advancing solar cell technology in terms of energy conversion efficiency improvement, as seen in the last decade. This has become a promising technology for next-generation, low-cost, high-efficiency photovoltaics including multi-junction tandem cell concepts. Double-junction tandem cells have much higher efficiency limits of 45%, beyond the Shockley–Queisser limits for a single-junction solar cell. In this review, recent progress with the perovskite tandem solar cells is highlighted, in particular, with 2-terminal perovskite–Si, perovskite–CIGS [where CIGS = Cu(In,Ga)(S,Se)2], perovskite–organic photovoltaic, perovskite–perovskite, and 3-junction-perovskite tandems. The opportunity and challenges of two-terminal monolithic perovskite tandems are discussed including a roadmap of strategies for further improving their efficiencies.

Limitations and solutions for achieving high-performance perovskite tandem photovoltaics

The large light absorption coefficient, long carrier diffusion length, and high defect tolerance enable organic-inorganic lead halide perovskites for excellent photovoltaic performance. The highest certified power conversion efficiency of single-junction perovskite solar cells (PSCs) has reported 25.5%. Besides, the bandgap of perovskites can be tuned by engineering their composition. These merits have made perovskites promising candidates for tandem photovoltaics, which can cross over the Shockley-Queisser limit of single-junction PSCs with economic costs. However, there are yet some hurdles in the wide-bandgap and narrow-bandgap subcells as well as interconnected layers (ICLs), which limit the commercial applications of perovskite tandem solar cells (PTSCs). In this review, we summarize the major scientific and technical limitations of PTSCs. We firstly demonstrate the configurations and working principles of PTSCs. Then, the developments of front subcells and rear subcells are discussed. Their main drawbacks, implemented technologies, and underlying mechanisms are analyzed in detail. Subsequently, the progress of ICLs which are responsible for guaranteeing continuous current in 2 T PTSCs are discussed. In addition, the stability of PTSCs is also summarized. The purpose of this review is to map and thrive the future development of PTSCs.

Dehydration-Reaction-Based Low-Temperature Synthesis of Amorphous SnOx for High-Performance Perovskite Solar Cells.

The development of methodologies for synthesizing carrier-transporting materials is critical for optoelectronic device fabrication. Amorphous metal oxides have emerged as potential carrier transport materials for perovskite tandem solar cells and flexible electronics due to their ease of fabrication and excellent electronic properties. However, perovskite solar cells employing amorphous metal oxides as the electron-transporting layers (ETLs) remain inefficient. This research describes a moderate dehydration reaction for the low-temperature synthesis of amorphous SnOx. We investigated this amorphous SnOx as the ETL for perovskite solar cells and demonstrated a maximum power conversion efficiency (PCE) of 20.4%, the greatest efficiency ever attained with an amorphous metal oxide ETL produced below 100 °C. Remarkably, the device maintained 85% of its initial efficiency for more than 4800 h. Furthermore, flexible perovskite solar cells based on this amorphous SnOx have a maximum PCE of 11.7%. Finally, this amorphous SnOx was used to fabricate LEDs and exhibited a maximum external quantum efficiency of over 3%.

Organic-Inorganic Perovskite Films and Efficient Planar Heterojunction Solar Cells by Magnetron Sputtering.

Organic–inorganic halide perovskites have been widely used in photovoltaic technologies. Despite tremendous progress in their efficiency and stability, perovskite solar cells (PSCs) are still facing the challenges of upscaling and stability for practical applications. As a mature film preparation technology, magnetron sputtering has been widely used to prepare metals, metallic oxides, and some semiconductor films, which has great application potential in the fabrication of PSCs. Here, a unique technology where high‐quality perovskite films are prepared via magnetron sputtering for controllable composition, solvent‐free, large‐area, and massive production, is presented. This strategy transforms the perovskite materials from powder to thin films by magnetron sputtering and post‐treatment (vapor‐assisted treatment with methanaminium iodide gas and methylamine gas treatment), which is greatly favorable to manufacture tandem solar cells. The power conversion efficiency (PCE) of PSCs with perovskite films fabricated by magnetron sputtering is 6.14%. After optimization, high‐performance perovskite films with excellent electronic properties are obtained and stable PSCs with excellent reproducibility are realized, showing a PCE of up to 15.22%. The entirely novel synthetic approach opens up a new and promising way to achieve high‐throughput magnetron sputtering for large‐area production in commercial applications of planar heterojunction and tandem PSCs.

Radiation stability of mixed tin–lead halide perovskites: Implications for space applications

Mixed organic-inorganic halide perovskite solar cells (PSCs) have received considerable attention in recent years for their impressive solar to electrical power efficiency gains and potentially lower material and processing costs for optoelectronic applications. In addition to terrestrial applications, PSCs are of interest to the space power markets for their low cost, low weight, adaptability to flexible architectures, and tolerance to high energy particle irradiation (mainly protons and electrons). Here we investigate the properties of mixed formamidinium-methylammonium tin-lead iodide (FASn)0.6(MAPb)0.4I3 perovskites which lower the lead content as well as the bandgap, making them attractive for the low bandgap absorber material in tandem PSCs. Through current density-voltage (JV) characterization at lower temperatures, majority carrier transport is hindered and a barrier to photogenerated carrier extraction is evident. This is attributed to the thermally induced change of the bandgap of the absorber layer relative to the energy selective contacts in the device. We find that although the architecture used here hinders the performance at temperatures below 225 K, the tolerance to high energy (3.7 MeV) protons is impressive, considerably out-performing commercially available thin-film CIGS. These results suggest further improvements to structural and interface stability as well as lightweight encapsulation could lead to all perovskite flexible tandem arrays deployed for power generation on missions to low Earth orbit, the moon, Mars, and beyond.

Influence of contact electrode and light power on the efficiency of tandem perovskite solar cell: Numerical simulation

This paper presents our theoretical study of tandem perovskite solar cells, simulated using a solar cell capacitance one-dimensional tool. The simulation reveals that the efficiency reaches 30.88% while combining Methylammonium Lead Iodide (MAPbI3) and Methylammonium Tin Iodide (MASnI3) as an absorber. The present work has also analyzed the effects of different materials as an Electron Transport Layer and Hole Transport Layer, and the effects of back metal contact, absorber layers defects, light radiation power, light direction, etc. Molecular Dynamic study has found that the thermal properties of MAPbI3 and MASnI3 perovskite layers are favorable to the solar cell efficiency and performance. In addition, the effect of temperature variation on solar cell performance is investigated, and the impact of defect density of the absorber layer is also explored. It was found that low defect density is helpful to achieve high device performance. Moreover, the work function of the front metal contact plays an important role, and it should be more than 5.31 eV for the proposed devices to achieve high performance.