Heterojunction Solar Cells Research Articles

Influence of hydrogen doping of In2O3-based transparent conducting oxide films on silicon heterojunction solar cells

Influence of hydrogen doping of In2O3-based transparent conducting oxide films on silicon heterojunction solar cells

Designing and simulating of new highly efficient ultra-thin CIGS solar cell device structure: Plan to minimize cost per watt price

This research paper examines the execution of ultra-thin solar cells made from chalcopyrite copper indium gallium diselenide (CIGS). The study presents a new CIGS heterojunction solar cell structure, which includes a Cd-free tungsten disulfide (WS2) buffer layer and poly (3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT: PSS) passivation layer. The performance of the solar cell is raised by a back surface field (BSF). A highly recombining rear surface is kept away from minority carriers by a field created by further strong doping at the back. The structure is Ni/PEDOT:PSS/CIGS/WS2/ZnO/Al and has been estimated numerically using the Opto-electrical stimulation of semiconductor layers simulator SCAPS-1D. A high efficiency with a Back surface passivated layer of 25.70 % with Voc of 0.81 V, Jsc of 39.33 mA/cm2, and FF of 79.89 % and without passivated layer efficiency of 17.58 % with Voc of 0.73 V, Jsc of 32.18 mA/cm2, and FF of 74.78 % is found for the intended CIGS-based solar cell with WS2 buffer. The interface between CIGS and WS2 forms a band structure that resembles spikes. This structure is crucial in enhancing the outputs by reducing carrier recombination. The optimal thicknesses for the buffer and CIGS absorber layers are 0.02 μm and 0.2 μm, respectively. These findings help reduce the cost per watt of the solar cell. Fabrication at a mass production scale, minimizing the thickness will have a significant impact on reducing cost.

Study of defect density of copper vacancies in chalcogenide CuSbS2, CuSbSe2, CuBiS2, and CuBiSe2 heterojunction thin-film solar cells.

In the past decade, a new family of ternary chalcogenide absorber (TCA) materials MIMIIX2 (where MI = Cu, Ag, Pb; MII = Sb, Bi, In; and X = S, Se, Te) have been studied. The copper family of ternary chalcogenide CuSbS2 CuSbSe2 CuBiS2, and CuBiSe2 is an amazing absorber material for thin-film solar cells because of their suitable band gap, high absorption coefficient and inexpensive, nontoxic, environment friendly and sustainable nature. In the presented work, first time simulated defect density of copper vacancies in CuSbS2 (CAS), CuSbSe2 (CASe), CuBiS2 (CBS) and CuBiSe2 (CBSe) has based heterojunction thin-film solar cells (HJTFSCs) with buffer CdS, intrinsic i-ZnO, window ZnO: Al and back contact Mo and set the cell scheming ZnO: Al/i-ZnO/n-CdS/p-TCA/Mo using SCAPS 1D. Major focus of this paper is on the influence of copper vacancies defect density that impact on the performance of ternary chalcogenide with various parameters of solar cells, i.e. short-circuit current density (Jsc), open-circuit voltage (Voc), form factor (FF) and efficiency (η). The cell parameter set at constant temperature 300K, thickness 2.5μm, carrier density 5 × 1016cm-3, front internal transmission coefficient 1 and illumination intensity 100 mW/cm2 with AM1.5 sun light. This study clarifies the potential benefits to utilizing of ternary chalcogenide compounds as absorber material for solar cell fabrication.

Performance improvement of inverted bulk heterojunction solar cells by use of gold nanoparticles modified PEDOT: PSS as an anode buffer layer

Performance improvement of inverted bulk heterojunction solar cells by use of gold nanoparticles modified PEDOT: PSS as an anode buffer layer

Enhancing photovoltaic applications through precipitating agents in ITO/CIS/CeO2/Al heterojunction solar cell

In this groundbreaking study, we successfully synthesized both cerium oxide and copper indium sulphate nanoparticles via co-precipitation method and the same is spray coated on ITO substrate by Jet Nebulizer Spray Pyrolysis (JNSP) technique. A comprehensive characterization of the structural, morphological and Photo-diode properties was conducted using a range of advanced techniques. X-ray diffraction revealed a superior mono-crystalline cubic fluorite structure with a preferred orientation along the (111) plane, indicating exceptional crystal quality. Scanning electron microscopy and transmission electron microscopy images showed the formation of disk-shaped particles with sharp rounded edges, averaging ∼ 5 nm in size. Fourier transform infrared spectroscopy identified the phonon band envelope of the metal oxide (CeO2) network at 848 cm−1 while photoluminescence spectroscopy revealed blue and blue-green emission in the visible spectrum. Thermogravimetric-differential thermal analysis exhibited a total weight loss of 19.52 % with four distinct exothermic and endothermic peaks. X-ray photoelectron spectroscopy confirmed the presence of Ce and O elements, with a minor amount of carbon absorbed from the atmosphere and revealed the dominant occurrence of Ce4+ and minority occurrence of Ce3+. The maximum power conversion efficiency of 0.23 % was achieved for samples prepared using NH3 precipitant making them highly suitable for photovoltaic applications. This work paves the way for future research in optimizing cerium oxide nanoparticles for high-performance photovoltaic devices potentially leading to breakthroughs in renewable energy harvesting.

Exploring Multi‐Level ETL and HTL Configurations for High‐Efficiency Lead‐Free Cs2AgBiBr6 Double Perovskite Solar Cells: A Design and Simulation Study

Cs2AgBiBr6 is a promising lead‐free double perovskite solar cells (PSCs) material. Its full potential has yet to be realized due to issues with its large band gap and the optimization of the alignment of the electron transport layer (ETL) and hole transport layer (HTL). The photovoltaic performance of Cs2AgBiBr6‐based devices has been optimized using ZnO, IGZO, TiO2, WS2, PCBM, and C60 ETLs and Cu2O, CuScN, CuSbS2, NiO, P3HT, PEDOT: PSS, Spiro MeOTAD, CuI, CuO, V2O5, CBTS, and CFTS HTLs. It has been observed by simulation study that Cs2AgBiBr6‐based devices exhibit remarkably high photoconversion efficiency when combined with certain ETLs. To better understand the performance, we examine how the best device structures are affected by the absorber and ETL thickness, ETL carrier density, series and shunt resistance, generation, and recombination rate. The findings suggest that TiO2 and ZnO ETLs, in conjunction with CBTS HTL, exhibit good potential for producing high‐efficiency (η > 13%) Cs2AgBiBr6‐based heterojunction solar cells with an ITO/ETL/Cs2AgBiBr6/CBTS/Au device structure. Optimization of the valence band offset (VBO) at the CBTS/Cs2AgBiBr6 interface reveals that reduced VBO value has a beneficial impact on the performance of the solar cell. This modeling work gives a prospective route for manufacturing lead‐free Cs2AgBiBr6 PSCs.

Se‐Elemental Concentration Gradient Regulation for Efficient Sb2(S,Se)3 Solar Cells with High Open‐Circuit Voltages

Antimony selenosulfide (Sb2(S,Se)3), featuring large absorption coefficient, excellent crystal structure stability, benign non‐toxic characteristic, outstanding humidity and ultraviolet tolerability, has recently attracted enormous attention and research interest regarding its photoelectric conversion properties. However, the open‐circuit voltage (Voc) for Sb2(S,Se)3‐based photovoltaic devices is relatively low, especially for the device with a high power conversion efficiency (η). Herein, an innovative Se‐elemental concentration gradient regulation strategy has been exploited to produce high‐quality Sb2(S,Se)3 films on TiO2/CdS substrates through a thioacetamide(TA)‐synergistic dual‐sulfur source hydrothermal‐processed method. The Se‐elemental gradient distribution produces a favorable energy band structure, which suppresses the energy level barriers for hole transport and enhances the driving force for electron transport in Sb2(S,Se)3 film. This facilitates efficient charge transport/separation of photogenerated carriers and boosts significantly the Voc of Sb2(S,Se)3 photovoltaic devices. The champion TA‐Sb2(S,Se)3 planar heterojunction (PHJ) solar cell displays an considerable η of 9.28% accompanied by an exciting Voc rising to 0.70 V that is currently the highest among Sb2(S,Se)3‐based solar cells with efficiencies exceeding 9.0%. This research is anticipated to contribute to the preparation of high‐quality Sb2(S,Se)3 thin film and the achievement of efficient inorganic Sb2(S,Se)3 PHJ photovoltaic device.

Se-Elemental Concentration Gradient Regulation for Efficient Sb2(S,Se)3 Solar Cells With High Open-Circuit Voltages.

Antimony selenosulfide (Sb2(S,Se)3), featuring large absorption coefficient, excellent crystal structure stability, benign non-toxic characteristic, outstanding humidity and ultraviolet tolerability, has recently attracted enormous attention and research interest regarding its photoelectric conversion properties. However, the open-circuit voltage (Voc) for Sb2(S,Se)3-based photovoltaic devices is relatively low, especially for the device with a high power conversion efficiency (η). Herein, an innovative Se-elemental concentration gradient regulation strategy has been exploited to produce high-quality Sb2(S,Se)3 films on TiO2/CdS substrates through a thioacetamide(TA)-synergistic dual-sulfur source hydrothermal-processed method. The Se-elemental gradient distribution produces a favorable energy band structure, which suppresses the energy level barriers for hole transport and enhances the driving force for electron transport in Sb2(S,Se)3 film. This facilitates efficient charge transport/separation of photogenerated carriers and boosts significantly the Voc of Sb2(S,Se)3 photovoltaic devices. The champion TA-Sb2(S,Se)3 planar heterojunction (PHJ) solar cell displays an considerable η of 9.28 % accompanied by an exciting Voc rising to 0.70 V that is currently the highest among Sb2(S,Se)3-based solar cells with efficiencies exceeding 9.0 %. This research is anticipated to contribute to the preparation of high-quality Sb2(S,Se)3 thin film and the achievement of efficient inorganic Sb2(S,Se)3 PHJ photovoltaic device.

Correction: The Copper Oxide with Alkali Potassium Dopant for Heterojunction Solar Cells Application

Correction: The Copper Oxide with Alkali Potassium Dopant for Heterojunction Solar Cells Application

Deeper Insight into the Mechanisms Behind Sputter Damage in Silicon Solar Cells Based on the Example of Nanocrystalline Silicon Carbide

AbstractTransparent conducting oxides, like indium tin oxide, enable lateral charge carrier transport in silicon heterojunction solar cells. However, their deposition can damage the passivation quality in the solar cell. This damage during the sputter deposition is a complex issue that has not been fully understood, particularly in various silicon‐based materials like amorphous silicon, polycrystalline silicon, or nanocrystalline silicon carbide. The degradation in passivation quality observed in, for example, amorphous silicon is not only explainable by UV light degradation. This study explores the origin of this degradation based on the example of hydrogenated nanocrystalline silicon carbide by combining simulations with experimental analyses. It delves into potential sources of damage during the sputtering process and determines that neither primary nor secondary effects from plasma luminescence or electron bombardment are likely contributors to the damage. Similarly, the implantation of ions, as well as the creation of vacancies and ionization of lattice atoms, are also considered improbable causes. It is, however, proposed that the transfer of energy to the crystalline silicon interface via phonons can factor into the degradation of the passivation quality. This transfer might be a plausible explanation for the damage observed in the passivation layers during the sputtering process.

Solar-Powered Gram-Scale Ammonia Production from Nitrate.

The photoelectrochemical (PEC) method has the potential to be an attractive route for converting and storing solar energy as chemical bonds. In this study, a maximum NH3 production yield of 1.01g L-1 with a solar-to-ammonia conversion efficiency of 8.17% through the photovoltaic electrocatalytic (PV-EC) nitrate (NO3 -) reduction reaction (NO3 -RR) is achieved, using silicon heterojunction solar cell technology. Additionally, the effect of tuning the operation potential of the PV-EC system and its influence on product selectivity are systematically investigated. By using this unique external resistance tuning approach in the PV-EC system, ammonia production through nitrate reduction performance from 96 to 360mg L-1 is enhanced, a four-fold increase. Furthermore, the NH3 is extracted as NH4Cl powder using acid stripping, which is essential for storing chemical energy. This work demonstrates the possibility of tuning product selectivity in PV-EC systems, with prospects toward pilot scale on value-added product synthesis.

Mechanism of photon-induced performance changes in silicon heterojunction solar cells

Mechanism of photon-induced performance changes in silicon heterojunction solar cells

Interface band alignment engineering of ZnO/Si heterojunction solar cells with high open circuit voltage

Interface band alignment engineering of ZnO/Si heterojunction solar cells with high open circuit voltage

Insights into mechanism of UV-induced degradation in silicon heterojunction solar cells

The ultraviolet-induced degradation (UVID), with losses of up to 11 % after 2000 h-exposure (Sinha et al., 2023) [1], impairs long-term stability of silicon heterojunction (SHJ) solar cells at present. However, the mechanism of UVID has remained only roughly understood till now. Herein, we shed light on the electrical properties of defects in SHJ solar cells to elucidate the underlying mechanism. Defect generation in SHJ solar cells after ultraviolet (UV) irradiation can be observed from photoluminescence (PL) images. Furthermore, we extract the density of states near Fermi level in hydrogenated amorphous silicon (a-Si:H) through analyzing carrier transport mechanism, and find the increment of state density induced by the UV irradiation. In conjunction with Fourier-transform infrared (FTIR) spectra, we ascribe the UV-induced defects to the rupture of Si–H and Si–H2 bonds. Besides, the intersection point between Fermi levels of the c-Si and a-Si:H/c-Si interface can be found shift toward valence band from admittance spectrum analysis, which is the cause of the higher interface state density based on the theory of Fermi energy dependent hydrogen diffusion energy. As a result, a potential mechanism of generation of recombination centers responsible for UVID in SHJ solar cells is proposed, which could provide insights into the possible solutions for UVID and enhance the long-term stability of SHJ solar cells.

Carrier transport mechanisms and photovoltaic performance of Ag/MoOx/Ag/MoOx/n-Si/C60/Al heterojunction solar cell

Carrier transport mechanisms and photovoltaic performance of Ag/MoOx/Ag/MoOx/n-Si/C60/Al heterojunction solar cell

Degradation of MoOx Thin‐Films Properties in Excessive Oxygen Environments and Its Influence on Dopant‐Free Silicon Solar Cells

Transition metal oxides such as molybdenum oxide (MoOx) demonstrate significant potential as efficient hole‐selective passivating contacts in silicon heterojunction solar cells. Achieving efficient hole collection necessitates precise control over the optical and electrical properties of MoOx films. In this study, the effects of oxygen flow rate () on the growth, optical properties, and electrical properties of thermally evaporated MoOx films are investigated. In the Kelvin probe force microscopy results, it is indicated that MoOx thin‐film deposition followed an island‐to‐layer growth model. X‐ray photoelectron spectroscopy shows that MoOx films exhibit stoichiometric composition with fully oxidized Mo6+ ions, without additional oxygen. Notably, the O 1s orbital peak shifts toward higher binding energy with increased , indicating defect introduction. Consequently, the work function of MoOx films decreases from 5.93 to 5.51 eV as increases from 0 to 8 sccm. The maximum optical bandgap of the MoOx films exceeds 3.60 eV. As a proof of concept, 's impact on MoOx as a front buffer layer for dopant‐free silicon solar cells is analyzed. An efficiency of 20.8% was achieved for dopant‐free silicon solar cells after optimized MoOx film deposition, with an open‐circuit voltage of 713.7 mV, short‐circuit current density of 39.1 mA cm−2, and fill factor of 74.6%.

Long exciton diffusion distance and efficient exciton dissociation enable high efficiency planar heterojunction non-fullerene organic solar cells

We characterized exciton diffusion and dissociation behaviour in two ITIC derivatives non-fullerene acceptors (NFA) by time-resolved spectroscopic methods. The exciton diffusion length was determined to be ∼26 and ∼34 nm in ITIC and IT4F. We further examined the dissociation of excitons in those NFA at the acceptor/donor planar heterojunction interfaces by transient absorption measurements, in which efficient charge generation was observed. Finally, we fabricated planar heterojunction solar cells using PM6/NFA bilayer planar heterojunctions; a power conversion efficiency (PCE) of over 7 % for PM6/IT4F bilayers was determined. More importantly, the spin-coating of top layer NFA has negligible influence on the morphology of the PM6 layer, suggesting a clear bilayer interface, rather than a quasi-bilayer structure with a portion of bulk heterojunction. The results suggest that enhanced exciton diffusion length and efficient exciton dissociation and charge generation are elemental characters to realize high PCE planar heterojunction organic solar cells. We established direct linking between the exciton diffusion length and the photocurrent generation in NFA layer by transfer matrix simulation. The large exciton diffusion length in NFAs makes the realization of high efficiency and stable bilayer organic solar cells feasible.

Optimizing inorganic SnS/ZrS2 heterojunction solar cells: Numerical analysis and performance insights

The SnS and ZrS2 have emerged as promising photovoltaic materials. This paper gives the first numerical analysis of inorganic SnS/ZrS2 heterojunction solar cells using SCAPS-1D. The study focuses on the effect of several parameters, such as thickness, doping charge carrier concentration, and energy bandgap, on fundamental solar cell properties in both the window and active layers. Our findings show that a variety of parameters influence solar cell performance, including built-in voltage, minority charge carrier lifetime, depletion breadth, charge carrier collection length, photogenerated current, and recombination rate. The maximum efficiency (η) attained in our simulated devices was 32.13 %, with FF of 84.51 % and Voc of 0.796 V. To achieve this efficiency, particular SnS parameters were used, such as a band gap of 1.00 eV, thickness of 5.0 μm, and doping charge carrier concentration of 1020 cm−3. In ZrS2, characteristics such as a band gap of 1.2 eV, thickness of 0.2 μm, and doping charge carrier content optimized 1020 cm−3 contribute to the observed efficiency. Our simulation results indicate that inorganic SnS/ZrS2 heterojunction devices have potential for solar device production that is cost-effective, large-scale, and high-efficiency. High performance enables a new path toward clean energy.

Study of the Effect of Exciton Annihilation Lifetime on Some Kinematic and Intrinsic Parameters of a Silicon Heterojunction Solar Cell (HIT), Illuminated by Monochromatic Light

In this article, with a view to improving the efficiency of photovoltaic cells, and given the promising yields of silicon heterojunction photovoltaic cells, we have, using a silicon heterojunction cell (a-Si:H/c-Si) doped with (n+p) , studied the contribution of excitons to the internal quantum efficiency of charge carriers. We then developed a detailed explanation of the energy conversion phenomena, based on an exciton-exciton annihilation process, which allows the electrons of quasiparticles to retain some of their energy. We used a numerical method for solving the charge carrier transport equations and carried out some additional calculations, which enabled us to obtain some results. These results then enabled us to study the influence of the annihilation lifetime on the charge carrier photo-current density, leading to internal charge carrier quantum yields of between 29.29768% and 77.8525%.

Eliminating Hole Extraction Barrier in 1D/3D Perovskite Heterojunction for Efficient and Stable Carbon-Based CsPbI3 Solar Cells with a Record Efficiency.

Carbon-based perovskite solar cells (C-PSCs) have the advantages of low-cost and high-stability, but their photovoltaic performance is limited by severe defect-induced recombination and low hole extraction efficiency. 1D perovskite is proven to effectively passivate the defects on the perovskite surface, therefore reducing non-radiative recombination loss. However, the unsuitable energy level of most 1D perovskite renders an undesired downward band bending for 3D perovskite, resulting in a high hole extraction barrier and reduced hole extraction efficiency. Therefore, rational design and selection of 1D perovskites as the modifiers are essential in balancing defect passivation and hole extraction. In this work, based on simulation calculations, thiocholine iodide (TchI) is selected to prepare 1D perovskite with high work function and then constructs TchPbI3/CsPbI3 1D/3D perovskite heterojunction. Experimental results show that this strategy eliminates the hole extraction barrier at the perovskite/carbon interface, which improves the hole extraction efficiency of corresponding devices. Meanwhile, the strong interaction between the thiol group and Pb suppresses defect-induced recombination effectively and improves the stability of CsPbI3. The assembled C-PSCs exhibit a champion efficiency of 19.08% and a certified efficiency of 18.7%. To the best of the knowledge, this is a new efficiency record for inorganic C-PSCs.