Performance Of Solar Cells Research Articles

Lithium and sodium ion Co-doping: A promising strategy for enhancing the performance of Cs2AgBiBr6 perovskite solar cells

The non-toxic perovskite Cs2AgBiBr6 presents impressive photovoltaic performance and stability, offering a lead halide-free alternative for solar cells. Overcoming challenges related to thin-film preparation and its intrinsic indirect bandgap, we leverage the synergistic effect of co-doping with lithium ions (Li+) and sodium ions (Na+) to enhance perovskite solar cells (PSCs). Improved carrier transport in Cs2AgBiBr6 films, facilitated by the diffusion of Li+, significantly enhances the photovoltaic conversion efficiency (PCE). Systematic exploration of various doping ratios identifies the optimal co-doping ratio, resulting in a remarkable PCE increase to 5.02 % and a short-circuit current of 6.56 mA cm−2. Ion doping not only tunes the material's band gap but also adjusts the energy level arrangement within the device layers. Impressively, the PCE of co-doped PSCs experiences only a 16.8 % decline after 60 days in an unencapsulated environment, underscoring its outstanding stability. This work provides a rational design for double-ion co-doping experiments, enhancing PSC performance and offering valuable insights for the future development of PSCs.

Interpretation of the degradation and trends in the performance of heterojunction silicon solar cells at low temperature

A compact model that combines numerical simulations using AFORS-HET and accurate equivalent circuit modelling is proposed and used to interpret the origins of the degradation and anomality's in the performance of the a-Si:H/c-Si heterojunction solar cells and its parameters at low temperature. The interpretations are applied to several trends reported on real cells. It is shown that as T decreases the a-Si:H(i) layer is depleted gradually from holes and that the cell operation fails once the layer is totally depleted and becoming intrinsic. The failure is caused by a substantial and sharp increase in the cell series resistance causing the collapse of the fill factor and of the cell current. It is found that at low temperature the open circuit voltage is significantly affected and its temperature dependence strongly distorted by hole depletion in the a-Si:H(i) spacer especially when the TCO work function is not appropriate. It is aslo shown that the S-shape in the cell I-V characteristics under illumination is closely linked to the TCO barrier reverse saturation current which explains its higher probability of appearnce at low temperature. Finally, it is concluded that the HJT cell would perform optimally down to the low 200 K range when the a-Si:H(p) is heavily doped and the front contact is ideally ohmic. Failing to satisfy such conditions the temperature range in which the HJT cell is useful is very limited.

Fabrication of high-efficiency perovskite solar cells using benzodithiophene-based random copolymeric hole transport material

The design of donor-acceptor (D-A)-based random copolymers-type hole transporting materials (HTMs) are important for achieving superior performance of perovskite solar cells (PSCs) with high durability. In this work, a 2-alkylthienyl-substituted benzodithiophene (BDTT)-based random copolymer (denoted as RCP-BDTTPD), containing 2-ethylhexylthiophene-substituted benzo[1,2-b:4,5-b′]dithiophene (BDTT as an electron-donor; M1) and two different side-chain functionalized thieno[3,4-c]-pyrrole-4,6‑dione as the electron-acceptors (M2 and M3), is prepared and applied as an efficient interfacial HTM for PSCs. The optical, electrochemical, and electronic properties of RCP-BDTTPD are shown to be structurally and energetically viable to serve as HTM for PSCs. The RCP-BDTTPD has deeper highest occupied molecular orbitals (HOMO; −5.53 eV) and lowest unoccupied molecular orbitals (LUMO; −3.57 eV) energy levels. This is shown to be energetically suitable for realizing better compatibility with Cs-containing formamidinium/methylammonium (FAMA) mixed-cation perovskite as light absorber having HOMO energy level (−5.85 eV). The RCP-BDTTPD possessing gradient band alignment with perovskite, which is shown to be highly significant for the extraction of charge carriers, resulting in higher hole mobility of PSCs. RCP-BDTTPD delivered a reasonably good Voc of 1.10 V and higher Jsc of 19.01 mAcm−2 and, champion power conversion efficiency (PCE) up to 15.30 % with hole mobility (1.34×10−3 cm2V−1s−1) and high durability (Encapsulated cell retention of its PCE about 98 % over 16 h under harsh environment: Temp. ∼85 °C, RH∼85 %). This work demonstrating a potential application of RCP-BDTTPD based HTMs for the fabrication of high-performance PSCs with high durability as well as low cost.

Enhancing Efficiency and Performance of Non-Fullerene Acceptor-Based Organic Solar Cells with Graphene Interlayer via Numerical Simulation

Enhancing Efficiency and Performance of Non-Fullerene Acceptor-Based Organic Solar Cells with Graphene Interlayer via Numerical Simulation

Extending Shelf-Life of Two-Step Method Precursor Solutions through Targeted Regulation for Highly Efficient and Reproducible Perovskite Solar Cells.

Precursor solution aging process can cause significant influence on the photovoltaic performance of perovskite solar cells (PVSCs). Notably, we first observe that the aging phenomenon is more severe in the precursor of two-step sequential method compared to that in one-step method due to that the protic solvent isopropanol facilitates amine-cation side reaction and iodide ions oxidation. Herein, we report a novel approach for selectively stabilizing both organic amine salt and lead iodide (PbI2) precursor solutions in two-step method. The introduction of benzene-1,3-dithiol into organic amine salt solution can mitigate amine-cation side reactions due to the formation of an acidic and reducing environment. Simultaneously, decamethylferrocene (FcMe10/FcMe+ 10) pair can act as a redox shuttle in PbI2 solution to concurrently oxidize Pb0 and reduce I2 in cyclic manner. Consequently, the PVSCs device fabricated from ameliorative precursor solutions demonstrates superior power conversion efficiency of 25.31 %, retaining 95 % of its efficiency after 21 days of solution aging. Moreover, the unencapsulated devices maintain 85 % of primitive efficiency for 1500 h at maximum power point tracking under continuous illumination. This work establishes a fundamental guidance and scientific direction for the stabilization of two-step perovskite precursor solutions.

Comprehensive device simulation of perovskite solar cell with CuFeO2 as hole transport layer

Abstract Solid-state organic-inorganic halide perovskite solar cells have attracted increasing interest due to their potential as high-efficiency, low-cost photovoltaic devices. In this study, we comprehensively simulate CH₃NH₃PbI₃ perovskite-based solar cells with CuFeO₂ as the hole transport material (HTM) layer, and compare them to cells using Spiro-OMETAD and Cu₂O as HTM layers, utilizing SCAPS-1D software. The effects of absorber thickness, back contact work function, CuFeO₂ thickness, acceptor concentration, and defect density at the CH₃NH₃PbI₃/CuFeO₂ interface are analyzed. The results indicate that delafossite CuFeO₂ is a promising HTM that could significantly enhance the performance of perovskite-based solar cells. TiO₂/CH₃NH₃PbI₃/CuFeO₂ solar cells demonstrate comparable photovoltaic performance to those using traditional Spiro-OMETAD when the back contact electrode work function exceeds 4.9 eV, and superior performance compared to those with Cu₂O and Spiro-OMETAD at work functions below 4.8 eV. A high acceptor concentration exceeding 10¹⁶ cm⁻³ in CuFeO₂ is recommended to achieve optimal photovoltaic performance. These simulation results highlight the significant potential of employing CuFeO₂ as an HTM layer in CH₃NH₃PbI₃ perovskite-based solar cells as an alternative to the organic Spiro-OMETAD.

Extending Shelf‐Life of Two‐Step Method Precursor Solutions through Targeted Regulation for Highly Efficient and Reproducible Perovskite Solar Cells

AbstractPrecursor solution aging process can cause significant influence on the photovoltaic performance of perovskite solar cells (PVSCs). Notably, we first observe that the aging phenomenon is more severe in the precursor of two‐step sequential method compared to that in one‐step method due to that the protic solvent isopropanol facilitates amine‐cation side reaction and iodide ions oxidation. Herein, we report a novel approach for selectively stabilizing both organic amine salt and lead iodide (PbI2) precursor solutions in two‐step method. The introduction of benzene‐1,3‐dithiol into organic amine salt solution can mitigate amine‐cation side reactions due to the formation of an acidic and reducing environment. Simultaneously, decamethylferrocene (FcMe10/FcMe+10) pair can act as a redox shuttle in PbI2 solution to concurrently oxidize Pb0 and reduce I2 in cyclic manner. Consequently, the PVSCs device fabricated from ameliorative precursor solutions demonstrates superior power conversion efficiency of 25.31 %, retaining 95 % of its efficiency after 21 days of solution aging. Moreover, the unencapsulated devices maintain 85 % of primitive efficiency for 1500 h at maximum power point tracking under continuous illumination. This work establishes a fundamental guidance and scientific direction for the stabilization of two‐step perovskite precursor solutions.

A Comprehensive Modeling on MoS2 Interface and Defect Engineering in CZTS Thin Film Solar Cells

This work uses the SCAPS-1D modeling program to examine the effects of faults in the molybdenum Disulfide (MoS2) layer and the MoS2 interface on the electrical performance of CZTS solar cells. To get an ideal energy gap (Eg) of 1.3 eV and a carrier concentration (CC) of 1014 cm⁻³, the research attempts to optimize the CZTS absorber layer. By maintaining a consistent doping level with 1016 cm-3 ≤ CC and an Eg within 1.6 eV < Eg ≤ 1.8 eV for the MoS2 film, the work also investigates the possibility of increased efficiency in CZTS/MoS2 devices. The study results indicate that open circuit voltage (VOC) and Efficiency (Eta-η) parameters are improved by a p-type MoS2 interface, indicating a promising development for CZTS solar systems. Nonetheless, n-type MoS2 suggests a compromise with a reduction in the fill factor. The study emphasizes the stability benefits of a p-type MoS2 interface as well as the importance of surface recombination velocity. The study also considers phase transitions that occur during the manufacture of devices, highlighting the intrinsic n-type character of MoS2 and the importance of experimental methods in CZTS device optimization. After analyzing the effects of defects on carrier density, depletion width, and quantum efficiency, the study concludes that enhancing the performance of CZTS solar cells requires an acceptor-type interface with p-type MoS2. With recombination resistances of 443.92 Ω cm2, 1530.33 Ω cm2, 81.54 Ω cm2, and 93.82 Ω cm2, the SCAPS model shows zero series resistance at a particular site for the fundamental, optimized design using n-MoS2 and p-MoS2. In the end, the work sheds light on the possibilities for additional experimental studies to advance the technology of CZTS solar cells.

Enhanced the efficiency of carbon based perovskite solar cells via g-C3N4 as functional additives

The quality of perovskite layer plays an important role in the performance of perovskite solar cells. Various defects can arise during the crystal growth process of Perovskite thin film. However, by using additives. It is possible to effectively enhance crystallize and form high-quality perovskite films with improved morphology. g-C3N4, a carbon–nitrogen ring with delocalized π electrons and certain conductivity, facilitates the transport of charge carriers. When it is utilized as an additive in perovskite solar cells, g-C3N4 not only improves the quality and crystallinity of perovskite films, but also passivates defects. As a result of these improvements, the optimal efficiency for preparing carbon-based perovskite solar cells is 13.74 %. This represents a significant increase in photoelectric conversion efficiency from 10.39 % to 13.74 %, corresponding to a remarkable enhancement of 32.24 %. These findings provide valuable insights into the potential application of two-dimensional materials and carbon nitrogen ring for enhancing the performance of perovskite solar cells.

Achieving 11.23 % efficiency in CZTSSe solar cells via defect control and interface contact optimization

The high open-circuit voltage deficit (VOC, def) caused by structural imperfections in the absorber layer and charge loss during carrier transport is a critical barrier affecting the performance of Cu2ZnSn(S,Se)4 (CZTSSe) devices. In this work, Ag was added to the DMF-based Cu+-Sn4+ system, which significantly improved the crystal morphology and electrical properties of the absorber layer. Additionally, optimizing the selenization process not only reduced surface roughness and eliminated voids at the bottom of the absorber layer but also resulted in the formation of a MoSe2 back interface layer with a more suitable thickness. These measures collectively enhanced the overall quality of the absorber layer, reducing the formation of deep-level defect clusters and effectively boosting carrier transport efficiency. Consequently, the concentration of bulk and interfacial defects decreased, and the impact of potential barriers on carrier movement was minimized. With these comprehensive improvements, the power conversion efficiency of CZTSSe solar cells increased from 8.48 % to 11.23 %. Our research demonstrates that optimizing the structure of the absorber layer can effectively enhance the performance of CZTSSe solar cells, providing valuable insights for the fabrication of high-efficiency devices in the future.

Dual-site regulation approach for improving photoelectric performance of perovskite solar cells

High power conversion efficiency (PCE) and long-term stability are the keys to the commercialization of perovskite solar cells (PSCs). However, the defects of formamidinium lead tri-halide (FAPbI3) perovskite films limit the PCE of the device to the Shockley Queisser limit. The conventional strategies for enhancing the properties of perovskite films often pivot on the selective interaction between a passivating agent and a solitary constituent within the perovskite matrix. Herein, we present an alternative dual-site regulation approach using 6-fluorobenzamide (6-FB) to modulate the reaction kinetics of Pb and I, resulting in FAPbI3 films with fewer defects and significantly enhanced carrier lifetimes. 6-FB can not only passivate the uncoordinated Pb2+ defects and iodine vacancies. The optimized PSCs achieved a PCE of 25.03 % (certified at 24.25 %) with an area of 0.0625 cm2, and retained 94.1 % of their initial PCE after storage in ambient air (∼10 relative humidity, RH) for over 800 h. This method expands the scope of chemical interactions possible by leveraging the interaction between 6-FB and the perovskite.

Dielectric screening modulating charge carrier recombination in high-performance of CsPbI2Br carbon-based perovskite solar cells

As a type of ionic crystal, CsPbI2Br perovskite inevitably generates a significant number of defects during the rapid crystallization process that occurs from deposition to annealing. The non-radiative recombination of charge carriers caused by these defects severely limits the performance of perovskite solar cells (PSCs). Here, 2,2,2-trifluoroethylamine hydrochloride (F3EACl) with permanent dipole moment is devised to modify the perovskite interface. Highly electronegative trifluoro groups can accelerate the dielectric response of perovskite films, intensify the dielectric screening effect, and significantly suppress non-radiative recombination of charge carriers. Meanwhile, the –NH3+ group in F3EACl effectively passivates the defects at the perovskite surface, further alleviating the defect-induced carrier recombination loss. Consequently, the CsPbI2Br carbon-based PSCs treated with F3EACl achieved an impressive power conversion efficiency (PCE) of 14.69 % at a higher open-circuit voltage (1.28 V), along with excellent environmental stability. This work demonstrates a unique tactic to achieve efficient and stable PSCs by modulating charge carrier recombination utilizing the synergistic effects of dielectric screening and defect passivation.

Enhanced performance of perovskite solar cells using ZnO electron transport layer prepared under simultaneous UV irradiation and magnetic field

Enhanced performance of perovskite solar cells using ZnO electron transport layer prepared under simultaneous UV irradiation and magnetic field

Effect of substrate temperature on the performance of Sb2Se3 thin film solar cells fabricated by chemical-molecular beam deposition method

Antimony triselenide (Sb2Se3) stands as a promising candidate for photovoltaic (PV) applications due to its favorable material- and optoelectronic properties. However, the realization of further advancements in device efficiency is hindered by the substantial deficit in open-circuit voltage (VOC) attributed to the presence of multiple defect states and detrimental recombination losses.In this work, solar cells based on Sb2Se3 absorber layers deposited by chemical-molecular beam deposition method at substrate temperatures of 400 °C, 450 °C, and 500 °C. Due to the precise control of the Sb/Se ratio, Sb2Se3 thin films with stoichiometric composition were obtained, which was confirmed by energy-dispersive X-ray spectroscopy. The effect of substrate temperature on the morphology and electrical properties of Sb2Se3 thin-films were characterized by scanning electron microscopy and hot probe method. The PV performance of Mo/Sb2Se3/ZnCdS/CdS/ZnO/ITO/Au devices were investigated by current-voltage characteristics, and external quantum efficiency. The conductivity values tend to increase from 1.2 × 10–6 to 4.6 × 10–4 (Ω cm)-1 as the substrate temperature increased. Whereas, the trap-state density was determined between 7.3 × 1013 – 1.7 × 1014 cm-3 in the absorber layer by the space charge limited current method. Ultimatety, it has been shown that defect densities in Sb2Se3 films can be suppressed to some extent by optimizing the substrate temperature. Best solar cell performance of 5.36%, resulting from VOC of 476 mV, short-circuit current densit of 22.97 mA/cm−2, and fill factor of 49% at the substrate temperature of 450 °C.

A Critical Review on Various Buffer Layers used to Enhance the Photovoltaic Performance of Organic Solar Cells

Abstract: Due to the high need for sustainable energy sources, there has been a tremendous increase in SC (solar cell) production and research in recent years. Despite the fact that inorganic SC has led the SC consumer market due to its exceptional efficiency, its expensive and difficult manufacture method makes it unaffordable. Hence alternative technology for SC has been explored by researchers to overcome the draw backs of inorganic SC fabrication. OSC (organic solar cell) alternatively known as polymer SC has the advantage of having lightweight, low production cost, and simple device structure. During the last few years, significant attention has been given in order to overcome the material and technological barriers in OSC devices to make them commercially viable. Buffer layers play a significant part in improving the power conversion efficiencies in OSCs, thus it is necessary to comprehend the underlying microscopic mechanisms that underlie the advancements in order to support the current qualitative knowledge. In this review article, we have studied extensively the impact of different BLs (buffer-layer) in enhancing the PCE (power conversion efficiency) and absorption capabilities of OSCs.

Effect of ultra-thin ZnS passivation using ALD technique on the performance of heterojunction solar cells

Hybrid solar cells (HSCs) using poly (3,4-ethylenedioxy-thiophene) polystyrene sulfonate (PEDOT:PSS) and n-silicon provide heterojunctions with the potential of light trapping, cost effectiveness, and high efficiency. However, charge recombination at rear interface hampers built-in potential and power conversion efficiency (PCE). Here, a superior, conformal, and uniform ultra-thin layer of Zinc sulfide (ZnS) is deposited on rear interface using atomic layer deposition (ALD) technique. The ALD-deposited ZnS thin layer serves as a passivation, electron conductive, and hole-blocking layer. The optimized HSCs exhibit a remarkable PCE of 12.37 % alongside a high open-circuit voltage of 0.625 V and a substantial fill factor of 71.5 %. These advancements stem from enhanced back junction quality between n-Si and electrode. The outcomes demonstrate an effective suppression of charge recombination and enhanced charge transfer facilitated by ALD-deposited ZnS thin layer, resulting an improved photovoltaic performance.

Exploring the Structural and Optical Properties of MoSe2 for Solar Cell Performance

Abstract Efficient energy absorption is critical in perovskite solar cells (PSCs) for effective electron collection and mitigation of hole migration. Molybdenum diselenide (MoSe2) was produced using a simple hydrothermal process and subsequently studied for its structural and optical properties using various techniques, including XRD, RAMAN, FESEM, EDX, UV-Visible, BET, and XPS. The results show that the enhanced crystalline morphology, size, optical band gap, and surface area demonstrate promising attributes for solar cell applications. Furthermore, the I-V investigation reveals that MoSe2-based PSCs achieve a notable efficiency of electricity conversion is 7.97%. The increased performance is because of the greater surface area of MoSe2. which facilitates increased light absorption, and its ability to accelerate charge transfer within the electron transport layer. Moreover, the structural integrity of MoSe2 contributes significantly to its efficacy in converting solar energy into electrical energy. These findings underscore MoSe2 as a compelling candidate for advancing solar cell technologies, offering potential pathways for achieving higher efficiency and reliability in future solar energy systems.

Electric Orbit Raising Radiation-Induced Coverglass Darkening and Its Impact on III-V Multijunction Solar Cell Performance

Electric Orbit Raising Radiation-Induced Coverglass Darkening and Its Impact on III-V Multijunction Solar Cell Performance

Impact of Dilute DIO Additive on Local Microstructure of Fluorinated, pNDI-Based Polymer Solar Cells.

The performance of all-polymer solar cells is often enhanced by incorporating solvent additives during solution processing. In particular, blends based on the model all-polymer system PBDBT:N2200 have been shown to have increased short-circuit current and fill factor when processed with dilute diiodooctane (DIO). However, the morphological mechanism that drives the increase in performance is often not well understood due to limitations in common characterization techniques. In this study, it is shown that a combination of X-ray techniques with cryogenic high-resolution transmission electron microscopy (HRTEM) analysis can provide a quantitative and spatially resolved picture of polymer chain orientation and alignment in all-polymer blends. It is found that DIO induces vertical phase separation in PBDBT-2F:F-N2200 and increases donor crystallite thickness in the pi-stacking direction leading to an acceptor-rich film surface. However, it is also shown that DIO does not disrupt the formation of face-on donor-acceptor interfaces. These findings suggest that dilute DIO primarily affects crystalline domain formation in single component regions as opposed to mixed regions; thus, dilute DIO can impact vertical charge transport pathways without sacrificing donor-acceptor interfacial connectivity.

Interface-enhanced germanium selenide solar cells comprising an ultrathin and uniform antimony selenide buffer layer via hydrothermal approach

Germanium selenide (GeSe) is a promising thin film photovoltaic absorber material owing to its excellent optoelectronic properties, high stability, and low toxicity. Interface engineering by introducing an ultrathin antimony selenide (Sb2Se3) buffer layer between the CdS electron transport layer and GeSe absorber layer is an effective technique for enhancing solar cell performance. However, the key to this technique is the fabrication of a uniform and smooth Sb2Se3 buffer layer with minimal thickness. In this study, instead of the conventional closed-space sublimation method, a hydrothermal method was employed to slowly grow an Sb2Se3 buffer layer with a thickness of approximately 8 nm. The Se/Na2SO3 molar ratio in the selenium source during the hydrothermal synthesis was adjusted; a molar ratio of 1:2 led to an uneven Sb2Se3 buffer layer thickness, whereas a molar ratio of 1:10 resulted in the formation of Sb2O3 particles on the buffer layer surface. When the Se/Na2SO3 molar ratio was 1:6, a smooth, uniform, dense, and impurity-free Sb2Se3 buffer layer was obtained, achieving the highest efficiency of 3.33 % in a GeSe solar cell. Moreover, GeSe solar cells with hydrothermally grown Sb2Se3 buffer layers demonstrated superior device interface properties and efficiency comparable with those using Sb2Se3 buffer layers deposited via closed-space sublimation. This technique offers an effective method for steadily improving the performance of GeSe solar cells.