Solar Cell Configuration Research Articles

Hole-Transport Management Enables 23%-Efficient and Stable Inverted Perovskite Solar Cells with 84% Fill Factor

HighlightsA graded inverted solar cell configuration is developed by hole-transport management aiming to suppress interface defects-induced non-radiative recombination for efficient hole transport.NiOx-based inverted PSCs present a power-conversion-efficiency over 23% with a high fill factor of 0.84 and open-circuit voltage of 1.162 volts, one of the best performances reported so far for 1.56-electron volt bandgap formamidinium-based triple-halide perovskites.Devices show high operational stability over 1,200 h during T90 lifetime measurement under 1-sun illumination in ambient-air conditions.

Double‐Absorber CZTS/Sb2Se3 Architecture for High‐Efficiency Solar‐Cell Devices

The design and configuration of solar cells are critical for photovoltaic action and achieving high efficiency. Herein, the double‐absorber solar‐cell architecture of low‐bandgap Sb2Se3 and high‐bandgap Cu2ZnSnS4 (CZTS) absorbers for broader spectrum utilization leading to higher efficiency are comprehensively analyzed. The cost‐effective chalcogenides CZTS and Sb2Se3 for high‐efficiency dual‐absorber configuration to show the possibility of high wattage at a lower cost are taken. The crucial parameters of bandgap pair and thickness are optimized for synergetic device performance and optimal utilization of the incident spectrum. By introducing an additional absorber–absorber interface, the interfacial defect at CZTS/Sb2Se3 is lowered by optimizing the band offset for the efficient functioning of a double–absorber device. The proposed device has straightforward NiO/CZTS/Sb2Se3/AZO architecture suitable for low‐cost fabrication with high efficiency of 30.9%.

The effects of grating anatase on the photovoltaic performance of perovskite based solar cells

Stimulated by the extraordinary power conversion efficiency (PCE) of hybrid organic-inorganic perovskites (HOIP) based solar cells (SCs), the derivative studies on inorganic perovskites (IOP) based SCs have been intensely investigated. In order to overcome the disadvantages of CsPbBr3, most prominently the unfavorable larger band gap (2.3eV), a grating layer of mesoporous anatase TiO2(mp-TiO2) has been inserted into the conventional configuration of SCs. The grating layer acts as the electron transfer layer (ETL) and light absorption strengthening layer at the same time. Due to the combined effects, the increased contacting area increased the fill factor (FF) and enhanced light trapping in the grating layer increased the short-current density, the average PCE of IOP based SCs has increased from 5.67% to 7.58%, which is a ca. 34% increase relatively. Furthermore, research on traditional HOIP-based SCs is also conducted. Interestingly, the increasing PCE mechanism is quite different from their inorganic counterparts, which should be attributed to the strain effect of different film structures. Thus, the strain-induced defect charge-state transitions of MAPbI3 by the grating layer increased the open-circuit voltage (Voc); and similarly, the increased contacting area also increased the FF, resulting in a 13% increase for PCE.

Photovoltaic characteristics of ultrathin Cs2CuBiCl6 halide double perovskite based solar cell: theoretical studies

The strenuous task of managing overall stability and environmental hazards associated with regular halide single perovskites draws attention toward halide double perovskite (DP) as an alternative materials. These materials are relatively stable and potentially less-toxic and have been explored for various applications- optoelectronics, electrical, spintronics, etc. This article brings forth the photovoltaic promise of noble metal and pnictogen element based Cs2CuBiCl6 halide DP as an ultrathin absorber in solar cell configured with p-i-n geometry. The numerical simulation of Cs2CuBiCl6 based all-inorganic inverted solar cell configuration exhibits comparable power conversion efficiency of around 17.03% for a 100 nm ultrathin absorber in a single junction cell. We considered microscopic factors like radiative recombination coefficient, neutral and charged defects with their densities, intrinsic heat in the devices, and macroscopic quantity like thickness of constituent layers, including interfacial effect in the device. The simulated device shows better interfacial defect tolerance on either side of the absorber layer, good device tolerance to absorber defect density < 1016 cm−3 and tollerable 0.84% intrinsic heat (Peltier and Joule heat) fraction for the device. This article may provide a way forward for realizing Cs2CuBiCl6 halide DP absorber based solar cell with a predicted open-circuit voltage of 0.91 Volt and short-circuit density of 21.66 mA/cm2.

Experimental and numerical investigations on feasibility of inorganic KSnCl3 perovskite absorber and SWCNT-HTL for solar cells

Inorganic metal halide perovskite materials have attracted remarkable attention as light harvesters because of their promising optoelectronic merits and photovoltaic features like tunable band gaps, high charge carrier mobilities and greater absorption coefficients. In order to explore new inorganic perovskite materials for use in optoelectronic devices Potassium Tin Chloride (KSnCl3) has been experimentally synthesized using a supersaturated recrystallization technique at ambient conditions. The resultant nanoparticle (NP) specimens were analyzed for optical and structural properties by characteristic available techniques including scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and UV visible spectroscopy. Experimental investigations about structure reveals that KSnCl3 crystallizes in orthorhombic phase with particle size of 400–500 nm. SEM showed better crystallization and EDX confirmed the accurate structural composition. UV–Visible analysis indicated a prominent absorption peak at 504 nm, and the band gap is 2.70 eV. Theoretical investigations of KSnCl3 were also carried out via AB-initio calculations in Wein2k simulation program using modified Becke Johnson (mBJ) and generalized gradient approximations (GGA). Optical properties like extinction coefficient k (ω), complex parts of dielectric constant (ε1, ε2), reflectivity R (ω), refractive index n (ω), optical conductivity L (ω) and absorption coefficient α (ω) were examined and it was observed that . theoretical investigations were consistent with experimental findings. Incorporation of KSnCl3 as an absorber material along with single walled carbon nanotubes as p-type materials in (AZO/IGZO/KSnCl3/CIGS/SWCNT/Au) solar cell configuration have been investigated by SCAPS-1D simulation package. Open circuit voltage (Voc) of 0.9914 V, short circuit current density (Jsc) of 47.32067 mA/cm2 and a remarkable efficiency of 36.823% with has been predicted. Thermally stable KSnCl3 may become potential source in manufacturing of photovoltaic and optoelectronic applications on large scale.

Improvement experimental and numerical simulation of Cu2SnS3-based solar cells

This study presents the experimental and a solar performance of Cu2SnS3 copper-tin sulphide films (CTS). The CTS films were synthesised by a spray pyrolysis method as show the abstract figure and it was deposited on ordinary glass substrates via a very promising non-toxic solution spray pyrolysis process. Pulverisation times of 15, 30 and 45 min were used to study the effect of spraying time on the crystal structure and opto-electronic properties of Cu2SnS3 films. The morphology, composition and opto-electronic properties were investigated using X-ray diffractometer, Raman spectroscopy, EDS, SEM, UV–visible spectrophotometer and a four-point probe technique. In this work, a high quality of Cu2SnS3 films with tetragonal dominant phase and morphological homogeneity are obtained at 30 and 45 min of spraying solution with appropriate optoelectrical properties for solar PV applications. Based on the experimental optical response of the CTS-45min samples, we have carried out a numerical simulation of the photovoltaic solar cell using Cu2SnS3 as an absorbing layer. The simulated solar cell demonstrated a power conversion efficiency PCE of 20.34% with voltage open circuit Voc, short-circuit density Jsc and fill factor FF of 1.09 V, 24.60 mA/cm2 and 75.23%, respectively, corresponding to the SLG/Mo/Cu2SnS3/ZnS/ITO/Al solar cell configuration, with the ITO is the In-doped SnO2 material.

An extensive study on multiple ETL and HTL layers to design and simulation of high-performance lead-free CsSnCl3-based perovskite solar cells

Cesium tin chloride (CsSnCl3) is a potential and competitive absorber material for lead-free perovskite solar cells (PSCs). The full potential of CsSnCl3 not yet been realized owing to the possible challenges of defect-free device fabrication, non-optimized alignment of the electron transport layer (ETL), hole transport layer (HTL), and the favorable device configuration. In this work, we proposed several CsSnCl3-based solar cell (SC) configurations using one dimensional solar cell capacitance simulator (SCAPS-1D) with different competent ETLs like indium–gallium–zinc–oxide (IGZO), tin-dioxide (SnO2), tungsten disulfide (WS2), ceric dioxide (CeO2), titanium dioxide (TiO2), zinc oxide (ZnO), C60, PCBM, and HTLs of cuprous oxide (Cu2O), cupric oxide (CuO), nickel oxide (NiO), vanadium oxide (V2O5), copper iodide (CuI), CuSCN, CuSbS2, Spiro MeOTAD, CBTS, CFTS, P3HT, PEDOT:PSS. Simulation results revealed that ZnO, TiO2, IGZO, WS2, PCBM, and C60 ETLs-based halide perovskites with ITO/ETLs/CsSnCl3/CBTS/Au heterostructure exhibited outstanding photoconversion efficiency retaining nearest photovoltaic parameters values among 96 different configurations. Further, for the six best-performing configurations, the effect of the CsSnCl3 absorber and ETL thickness, series and shunt resistance, working temperature, impact of capacitance, Mott–Schottky, generation and recombination rate, current–voltage properties, and quantum efficiency on performance were assessed. We found that ETLs like TiO2, ZnO, and IGZO, with CBTS HTL can act as outstanding materials for the fabrication of CsSnCl3-based high efficiency (η ≥ 22%) heterojunction SCs with ITO/ETL/CsSnCl3/CBTS/Au structure. The simulation results obtained by the SCAPS-1D for the best six CsSnCl3-perovskites SC configurations were compared by the wxAMPS (widget provided analysis of microelectronic and photonic structures) tool for further validation. Furthermore, the structural, optical and electronic properties along with electron charge density, and Fermi surface of the CsSnCl3 perovskite absorber layer were computed and analyzed using first-principle calculations based on density functional theory. Thus, this in-depth simulation paves a constructive research avenue to fabricate cost-effective, high-efficiency, and lead-free CsSnCl3 perovskite-based high-performance SCs for a lead-free green and pollution-free environment.

Origin, Nature, and Location of Defects in PM6:Y6 Organic Solar Cells

AbstractTargeted strategies to overcome defects in organic semiconductors require insight into their identity and origin. Here the formation, nature, and location of defects is studied in PM6:Y6 organic solar cells by sensitive EQE measurements. Exposure of the active layer to ambient atmosphere and H2O‐saturated compressed air indicates that a trace constituent in ambient air causes the formation of defects. By exposing the active layer to O3‐enriched air, O3 is identified as the species creating defects in PM6:Y6 blends. Aging of complete inverted (n–i–p) configuration solar cells in H2O‐saturated compressed air also increases the defect response. This is attributed to a reduced band bending at the PM6:Y6 | MoO3 hole‐collecting contact, caused by a change in work function of MoO3 interacting with the H2O, which allows more defect states to be filled and available for photoexcitation. By measuring energy resolved‐electrochemical impedance spectroscopy and by fabricating semitransparent cells, regular architecture cells, and semitransparent cells with an optical spacer−mirror stack it is found that defects originate predominantly from PM6 and are located near the top electrode, independent of device polarity. Because O3 is omnipresent in ambient atmosphere, albeit in small amounts, it likely causes defects in many organic semiconductors exposed to ambient air.

Silicon-Perovskite combinational cell fabricated through a solution route

• Heterojunction of silicon-perovskite is fabricated by Al/Silicon/Perovskite/Ag. • Al/Silicon/Perovskite/Ag may be an alternative to silicon-perovskite Tandem cells. • The Al/Silicon/Perovskite/Ag heterojunction solar cell shows FF induced degradation. We will demonstrate an innovative silicon-perovskite combinational cell heterojunction diode formation via a solution route synthesis. The p or n-type of perovskite are formed by controlling the ratio of MA + to Pb + and have made films of these p/n types of perovskites on the n/p type of wafer to fabricate silicon-perovskite combinational cells of the structure of Al/Si(p-type)/Perovskite(n-type)/Ag. The champion cell of these innovative silicon-perovskite combinational heterojunction devices showing V oc , J sc , FF and efficiency ∼ 0.34 V, ∼ 4.23 x 10 -3 mA/cm 2 , ∼ 49.80%, ∼ 0.71 and ∼ 0.17 V, ∼ 3.86 x10 -3 mA/cm 2 , ∼ 61%, ∼ 0.43 respectively for first and second batch having 5 devices each. The T 80 value for both batches of devices is ∼ 5 days. This device structure is similar to the heterojunction with intrinsic thin layer (HIT) configuration of silicon solar cells.

Thermally Stable Perovskite Solar Cells by All-Vacuum Deposition.

Vacuum deposition is a solvent-free method suitable for growing thin films of metal halide perovskite (MHP) semiconductors. However, most reports of high-efficiency solar cells based on such vacuum-deposited MHP films incorporate solution-processed hole transport layers (HTLs), thereby complicating prospects of industrial upscaling and potentially affecting the overall device stability. In this work, we investigate organometallic copper phthalocyanine (CuPc) and zinc phthalocyanine (ZnPc) as alternative, low-cost, and durable HTLs in all-vacuum-deposited solvent-free formamidinium-cesium lead triodide [CH(NH2)2]0.83Cs0.17PbI3 (FACsPbI3) perovskite solar cells. We elucidate that the CuPc HTL, when employed in an "inverted" p-i-n solar cell configuration, attains a solar-to-electrical power conversion efficiency of up to 13.9%. Importantly, unencapsulated devices as large as 1 cm2 exhibited excellent long-term stability, demonstrating no observable degradation in efficiency after more than 5000 h in storage and 3700 h under 85 °C thermal stressing in N2 atmosphere.

Exploring the effect of oxygen environment on the Mo/CdTe/CdSe solar cell substrate configuration

Incorporating Se element into Cadmium telluride (CdTe)-based superstrate configuration solar cells have advanced impressively. However, molybdenum (Mo)/CdTe/CdSe substrate configuration devices remain relatively unexplored, and Mo foil oxidation behavior during the fabrication process is kept in the dark. This work investigates a fresh CdTe/CdSe substrate configuration solar cell using Mo substrates. Mo/CdTe/CdSe/ZnO/AZO/ITO solar cells have been fabricated, CdTe absorber layer was obtained by closed space sublimation (CSS) under ∼2000 pa pressure in varying Ar/O2 flu ratio. The champion device had an efficiency of 3.87% with unintentional Cu-doping and back contact. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-Ray spectroscopy (EDS) were applied to study the properties of CdTe films. Before CdTe deposition, molybdenum oxide (MoOx) was generated while heating the Mo substrate in an oxygen-containing environment. This buffer layer plays a pivotal role in blocking non-Ohmic back contact analyzed by current-voltage-temperature (J-V-T) measurements. Molybdenum oxidation states were extensively studied to build the relationship with a solar cell device. Our findings indicated that different oxygen partial pressure had less relevance with the CdTe surface chemical environment but was incredibly relevant for Mo metal foil oxidation states.

Finite element method description and intrinsic parameters extraction of solar cells with different sizes and metallization patterns

The current density-voltage (J−V) curve of a solar cell and the parameters extracted from that can describe the characteristics of the solar cell and can used for optimizing its front metallization pattern. Solar cells with different front metallization patterns or sizes correspond to different J-V curves. It is not sure which curve is more suitable for optimizing the front metallization pattern. In this paper, a method for extracting the intrinsic parameters of the one-diode model of solar cells is proposed. It is based on the finite element method (FEM) to construct solar cells and a genetic algorithm to solve the intrinsic parameters of solar cells. The effectiveness of FEM in constructing solar cells is verified by comparing the simulation results with previously published modeling results. Three different solar cell configurations are established to verify the validity of the proposed method. The results show that there is almost no difference in the intrinsic parameters extracted from solar cells of different sizes and metallization patterns. These intrinsic parameters are almost the same as the characteristic parameters of the unit cell used in the numerical model. This research is expected to become a fundamental study for optimizing the front metallization pattern of solar cells.

Optimization of tin based perovskite solar cell employing CuSbS2 as HTL: A numerical simulation approach

The expeditious progresses in the domain of organo-metallic halide perovskite solar cells has resulted in PCE of more than 25.5%. However, their extensive utilization and fully fledged commercialization is currently restricted owing to the existence of expensive hole transport layer (HTL) viz Spiro-OmeTAD in the novel devices. In this paper, a low cost and easily available materials i.e. CuSbS2 and fullerene (C60) are endeavored as HTL and ETL respectively, by utilizing SCAPS 1D simulator, which can also yield high solar cell performance. In this context, the analysis of Spiro-OmeTAD, CuSbS2 as HTLs and TiO2, C60 as ETLs has been validated. In addition, effect of thickness of HTLs on perovskite solar cells using CH3NH3SnI3 as light harvester & C60 as hole inhibiting layer/electron transport layer (ETL) has been also examined. The recommended simulation reveals that using 20 nm of CuSbS2 layer can outperform Spiro-OmeTAD as HTL for cell fabrication. It has been observed that by employing proposed perovskite solar cell configuration FTO/C60/CH3NH3SnI3/CuSbS2/Au, an efficiency (PCE) of 26.05% associated with fill factor (FF) of 82.98%, short circuit current (Jsc) of 31.646 mA/cm2 & open circuit voltage (Voc) of 0.9918 V can be yielded which assures exhibition of better solar cell performance than the existing solar cell.

New numerical model for a 2T-tandem solar cell device with narrow band gap SWCNTs reaching efficiency around 35 %

With a large-band gap top cell and a low-band gap bottom cell, double-junction tandem solar cells have a huge potential to exceed existing single-junction photovoltaic technology. To fully benefit, serious attention must go into the choice and performance amelioration of both cells. Tandem solar cells with two terminals (2 T) are highly efficient in converting energy. As the 2 T tandem solar cell configuration is equivalent to an electric series connection between the sub-cells, one of its key constraints is the circulation of current density. The monolithic device's performance is constrained because the sub-cell with the lowest current (top cell) forces it to run at its value. Using a bottom sub-cell made of Single-Walled Carbon Nanotubes (SWCNTs), which has an interesting current density and matches the top cell, is a possible solution for such a challenge as presented in this simulation work. The 2 T monolithic solar cell resulting from this study offers interesting photovoltaic parameters with an excellent fill factor and power conversion efficiency of 34.8 %.

Improvement of CZTSSe film quality and superstrate solar cell performance through optimized post-deposition annealing

Improving the performance of kesterite solar cells requires high-quality, defect-free CZTS(Se) films with a reduced number of secondary phases and impurities. Post-annealing of the CZTS films at high temperatures in a sulfur or selenium atmosphere is commonly used to improve the quality of the absorbing material. However, annealing at high-temperatures can promote material decomposition, mainly due to the loss of volatile elements such as tin or sulfur. In this work, we investigate how the additional step of sulfurization at reduced temperatures affects the quality and performance of CZTSSe based solar cells. A comprehensive structural analysis using conventional and high resolution XRD as well as Raman spectroscopy revealed that the highest CZTSSe material quality with the lowest structural disorder and defect densities was obtained from the CZTS films pre-sulfurized at 420 °C. Furthermore, we demonstrate the possibility of using Sb2Se3 as a buffer layer in the superstrate configuration of CZTSSe solar cells, which is possible alternative to replace commonly employed toxic CdS as a buffer layer. We show that the additional low-temperature selenization process and the successful use of Sb2Se3 as a buffer layer could improve the performance of CZTSSe-based solar cells by up to 3.48%, with an average efficiency of 3.1%.

Encapsulation Protocol for Flexible Perovskite Solar Cells Enabling Stability in Accelerated Aging Tests

Flexible perovskite solar cells (f‐PSCs) offer attractive commercial prospects in the near future, enabled by new value propositions, such as mechanical flexibility, or high specific powers. The long‐term reliability of these devices requires appropriate encapsulation to prevent degradation caused by environmental factors. Here, a lamination protocol is developed, incorporating adhesive materials, barrier foils, and edge sealants, which results in a robust device hermitization. By applying the developed procedure to three different perovskite solar cell configurations (p‐i‐n with carbon, p‐i‐n with silver, and n‐i with carbon), fabricated with large active areas (1 cm2), the universality of this approach is demonstrated. The best devices preserved over 85% of the initial performance after a sequence of accelerated aging tests based on industry standards (compliant with the IEC 61215 and IEC 61646) comprised of 1400 h of damp heat, 50 thermal cycles, and 10 cycles of the humidity‐freeze test.

Energy efficiency assessment of photovoltaic array on the stratospheric airship under partial shading conditions

Accurate estimation of efficiency of airborne photovoltaic array on the airship has great significance for ensuring sufficient energy to stay in the stratosphere for months or a year. The solar irradiation and thermal model of the solar-powered airship have been studied. However, the interaction among the solar cells with different working conditions in the array has not been investigated. In this paper, the four main causes of nonuniform operating conditions including installation angle, angular losses, flight condition, and temperature are analyzed. The circuit simulation method is proposed, which determines the appropriate connection configuration of solar cells on the curved surface of airship at first. Then, the circuit analysis model of the connected solar array is built in Simulink. The I–V and P–V characteristic curves of the solar array are solved, and the maximum power point is tracked. The overestimation of output power and energy efficiency caused by using the empirical prediction model can be over 42.5%, and can be avoided by the proposed method in this paper. The work also provides an interesting reference for researchers to investigate reconfiguration and optimization of solar array on airship.

2D or Not 2D: A Thermodynamic Approach to Modeling Space Solar Cells’ Efficiency with 2D Materials

Approximately 3 billion people have never used the internet due to its costs and inaccessibility, particularly in developing countries. To provide these areas with affordable internet, reducing the cost of building and launching satellites has become paramount in the assessment of their design, particularly their solar cells. While three-dimensional semiconductor materials like gallium arsenide (GaAs) have been the main material used in these cells to convert solar energy into electrical energy, two-dimensional (2D) materials like tellurene have demonstrated properties that warrant consideration. This research evaluates the potential of a novel 7-junction space solar cell configuration consisting of manganese phosphorus trisulfide, tungsten disulfide, rhenium disulfide, molybdenum disulfide, molybdenum ditelluride, bismuth oxyselenide, and tellurene to replace current 3-junction configurations using GaAs-based materials. Thermodynamic expressions, including the efficiency of a Carnot heat engine and a geometric optimization approach using the Shockley-Queisser triangle, were analyzed to derive equations for two properties critical to a space solar cell: efficiency and specific power. Computational simulations were run, and the results indicate that a 7-junction space solar cell configuration using 2D materials can enable a maximum efficiency gain of 12%, a mass reduction by over one-fifth, and a specific power output improvement of 54% at lower costs compared to GaAs-based space solar cells. The implications of this study point to the performance and cost feasibility of satellite usage for a broad range of applications, with social and environmental significance.

Ag‐Refined Kesterite in Superstrate Solar Cell Configuration with 9.7% Power Conversion Efficiency

AbstractThin‐film photovoltaic materials offer a sustainable solution to the current environmental and energy challenges, among which kesterite or Cu2ZnSn(S,Se)4 is of particular interest due to its earth‐abundant, non‐toxic nature, and realization of rapid efficiency improvement in earlier 2010s. In contrast to the majority of research on kesterite solar cells that relies on the substrate configuration, this study is pioneering in applying superstrate configuration to tackle the surface incompatibility challenges as well as the use of Cd‐based buffer layers encountered in the substrate configuration – issues that act as barriers in the deployment of this photovoltaic technology. By applying a Ag‐refining step on an ultrathin (Cu,Ag)2ZnSn(S,Se)4 with TiO2 buffer layer, a Cd‐free superstrate kesterite solar cell with efficiency of 9.7% – a record high efficiency in its class is reported. This refining step is crucial in increasing the ratio of Ag/(Cu+Ag) to 40%–60%, overcoming the limit of 35% set by efficient substrate devices. The promoted grain growth and improved charge transport kinetics (i.e., enhanced lifetime/extraction and reduced trap states) ultimately contribute to the boost of performance. Critical device/semiconductor characteristics reveal a majorly depleted absorber but with high density of back surface defects identified as the main limiting factor in device performance.

Insights into the charge carrier dynamics in perovskite/Si tandem solar cells using transient photocurrent spectroscopy

Direct bandgap perovskite and indirect bandgap Si, which form the two active layers in a tandem solar cell configuration, have different optoelectronic properties and thicknesses. The charge-carrier dynamics of the two-terminal perovskite-on-Si tandem solar cell in response to a supercontinuum light pulse is studied using transient photocurrent (TPC) measurements. Spectral dependence of TPC lifetime is observed and can be classified into two distinct timescales based on their respective carrier generation regions. The faster timescale (∼500 ns) corresponding to the spectral window (300–750 nm) represents the top-perovskite sub-cell, while the slower timescale regime of ∼25 μs corresponds to the bottom-Si sub-cell (&amp;gt;700 nm). Additionally, under light-bias conditions, the transient carrier dynamics of the perovskite sub-cell is observed to be coupled with that of the Si sub-cell. A sharp crossover from the fast-response to a slow-response of the device as a function of the light-bias intensity is observed. These results along with a model based on transfer matrix formulation highlight the role of charge-carrier dynamics in accessing higher efficiencies in tandem solar cells. The carrier transit times and lifetimes in addition to their optical properties need to be taken into account for optimizing the performance.