Planar Solar Cells Research Articles

Investigation on Absorption and Photocurrent in Silicon Absorber with Varied Pyramid Texture Angles by Ray Tracer

In this work, ray tracing is used to investigate the effects of pyramid texture angle towards light absorption and photocurrent in 250 μm-thick crystalline silicon (c-Si) absorber. Upright pyramids with texture angles of 10-50o are investigated. Planar c-Si absorber is used as a reference. When the pyramid angle increases, the broadband reflection reduces due to enhanced light scattering which leads to improved light absorption. At angle of 50o, the weighted average reflection (WAR) reduces to 14.7% and broadband light absorption increases. The optical path length enhancement increases to 12 at wavelength of 1100 nm. The reflection and photogenerated current density (Jg) exhibit an inverse relationship with increasing zenith angle. With increasing zenith angle, the reflection from the c-Si absorber increases and this results in lower light absorption and Jg. In the passivated emitter rear cell (PERC) solar cell, the planar solar cell exhibits short-circuit current density (Jsc) of 26 mA/cm2 with conversion efficiency of 13.6%. When both the pyramids and the silicon nitride (SiNx) anti-reflective coating (ARC) are incorporated on the solar cell, the Jsc increases to 39 mA/cm2 and conversion efficiency increases to 20.5%. This is attributed to the enhanced light-trapping and light-coupling effects in the device.

Suppressing Bimolecular Charge Recombination and Energetic Disorder with Planar Heterojunction Active Layer Enables 18.1% Efficiency Binary Organic Solar Cells

The performance of organic solar cells has been dramatically enhanced due to the use of bulk heterojunction active layer structure. However, blending donor and acceptor in the bulk volume results in a large extent of bimolecular charge recombination and increasing energetic disorder. Herein, we fabricated organic solar cells with polymer donor PM6 and nonfullerene acceptor N3 in bilayer structure to investigate the impact of planar heterojunction configurations on charge recombination and energetic landscapes. We find superior crystallinity features in the bilayer composed of pure donor and acceptor layers. The bimolecular charge recombination and energetic disorder are effectively suppressed compared with the bulk heterojunction counterparts. Thus, a power conversion efficiency as high as 18.1% (17.8% averaged) is achieved, which stands among the top values of planar heterojunction organic solar cells. In addition, improved device shelf stability is observed because of the fewer donor–acceptor interfaces in the active layer. Our results suggest that a planar heterojunction structure could efficiently suppress the bimolecular charge recombination and energetic disorder, providing an alternative pathway for developing solution-processed organic solar cells.

Optically‐Boosted Planar IBC Solar Cells with Electrically‐Harmless Photonic Nanocoatings

AbstractAdvanced light management via front‐coated photonic nanostructures is a promising strategy to enhance photovoltaic (PV) efficiency through wave‐optical light‐trapping (LT) effects, avoiding the conventional texturing processes that induce the degradation of electrical performance due to increased carrier recombination. Titanium dioxide (TiO2) honeycomb arrays with different geometry are engineered through a highly‐scalable colloidal lithography method on flat crystalline silicon (c‐Si) wafers and tested on standard planar c‐Si interdigitated back‐contact solar cells (pIBCSCs). The photonic‐structured wafers achieve an optical photocurrent of 36.6 mA cm−2, mainly due to a broad anti‐reflection effect from the 693 nm thick nanostructured coatings. In contrast, the pIBCSC test devices reach 14% efficiency with 679 nm thick TiO2 nanostructures, corresponding to a ≈30% efficiency gain relative to uncoated pIBCSCs. In addition, several designed structures show unmatched angular acceptance enhancements in efficiency (up to 63% gain) and photocurrent density (up to 68% gain). The high‐performing (yet electrically harmless) LT scheme, here presented, entails an up‐and‐coming alternative to conventional texturing for c‐Si technological improvement that can be straightforwardly integrated into the established PV industry.

Highly efficient SnS-based inverted planar heterojunction solar cell with ZnO ETL

Tin Sulfide (SnS) is a promising absorber material for solar energy harvesting owing to the high absorption coefficient. Here, a novel inverted planar heterostructure of SnS based solar cell (ITO/NiOX/SnS/ZnO/Al) has been proposed for better efficiency among the different electron transport layers (ETLs), PCBM, C60, CeOX, and ZnO. The performance of the SnS based solar cell was theoretically studied by the Solar Cell Capacitance Simulator (SCAPS) software. Initially, we have been observed the device performance with different ETL materials to find the better ETL material. The layer parameters of the HTL, absorber layer, and ETLs have been optimized to find out the best performance of the device. The device showed efficiencies of around 26.44%, 26.33%, and 26.38% with the ETLs PCBM, C60, and CeOX respectively. The maximum power conversion efficiency (PCE) of ∼28.15% has been observed after incorporating ZnO ETL in the designed architecture of the SnS-based solar cell. Then, we have been investigated the performance of the SnS-based solar cell with ZnO ETL for the various value of carrier concentration, thickness, and bulk defect of the SnS absorber layer, defect of the interfaces of NiOX/SnS and SnS/ZnO, back metal contact’s work function, and its operating temperature. The variation of the different parameters has exhibited a substantial effect on the device performance. The VOC, JSC, FF, and PCE of the optimized SnS-based solar cell with ZnO ETL showed 0.8954 V, 37.316452 mA cm−2, 84.24%, and 28.15%, respectively. The visualization of the results indicates that ZnO might be a potential ETL for the highly efficient, low-cost inverted planar solar cells based on SnS.

Determination of Defects in Planar CH3NH3PbI3 Perovskite Solar Cells Using a SCAPS-1D Simulation Tool

In this work, electrical simulations of planar CH3NH3PbI3 solar cells using a SCAPS-1D (a Solar Cell Capacitance Simulator) simulation tool were performed to determine the density of defects based on the performance parameters and J-V characteristics of actual experimental planar CH3NH3PbI3 solar cells. Two types of defects (bulk and interface) were introduced into the simulation model. The densities of those defects were found by fitting the J-V characteristics and performance parameters including , , and FF to the experimental data. The methods and results reported in this paper showed a close relationship between the parameters of defects in planar perovskite solar cells.
 
 

Preparation and characterization of Sb2S3 thin films for planar solar cells via close space sublimation method

Sb2S3 has a unique one-dimensional structure-composed (Sb4S6) n ribbons leads to strong anisotropic carrier transport characteristic: carrier transport along the (Sb4S6) n ribbon is more efficient than other ribbons. Therefore, it's crucial to control the direction of grain growth along the (hk1) orientation. In this work, the close space sublimation method was utilized to fabricate Sb2S3 thin films with a systematical regulation of substrate temperature. The results demonstrate that optimized Sb2S3 thin film presented preferred orientation at the direction of (hk1). The champion device based on Au and Ni electrodes achieved a power conversion efficiency (PCE) of 3.06% and 1.69%, respectively.

Nanorod array-induced growth of high-quality Sb2Se3 absorber layers for efficient planar solar cells

Antimony selenide (Sb2Se3) has been applied extensively in the field of optoelectronics because of its excellent material and photoelectric properties, as well as its potential low cost effectiveness. Owing to its unique quasi-one-dimensional structure, the preparation of an Sb2Se3 absorption layer with high crystallization quality and standing preferred orientation is crucial for constructing high-performance Sb2Se3 devices. Herein, we reported a new method for the subsequent epitaxial growths of Sb2Se3 thin films with high crystallization and preferred standing orientations using the Sb2Se3 nanorod array as growth template on the Mo substrate and summarized the growth mechanism of the nanorod arrays. High crystal quality and crystal orientation can be easily controlled, carrier recombination is reduced, charge transport is enhanced, and the performance of Sb2Se3 device is improved significantly. As high as 6.3 % power-to-efficiency with a fill factor of 62 % has been achieved for the champion device. This general-purpose nanorod array template growth film provides an effective reference for the growth control of other low latitude crystal films.

Design of hierarchical nanohole for efficient broadband light absorption of MAPbI3 perovskite material based solar cell with thin absorber layer

Perovskite solar cell has the advantages of low dosage of toxic materials, flexibility and consumer-oriented, which has significant development potential. Nanophotonic structure shows superior performance to common geometrical structure in controlling light transfer, which can capture and trap light, and thus improving the light absorption while reducing its thickness. In this work, novel wavelength-sized hierarchical nanohole is devised toward maximum broadband light absorption. The hierarchical nanohole can excite quasi-guided modes to improve light absorption, the electric field distribution is shown and demonstrated. The proposed perovskite solar cells with hierarchical nanohole outperform a planar solar cell by 17% in JSC and outperform a perovskite solar cell with one nanohole reference by 6.7% in JSC. In addition, the effects of hierarchical nanohole geometry on performance of perovskite solar cell are investigated. Overall, this work provides a new design for the ultra-thin perovskite solar cell with high energy conversion efficiency.

Confined‐Space Selenium‐Assisted Tellurization Posttreatment Strategy for Efficient Full‐Inorganic Sb2S3 Thin‐Film Solar Cells

Antimony sulfide is a promising photovoltaic material because of its high absorption coefficient, green and earth‐abundant constituents, and suitable bandgap. Sb2S3 planar solar cells from evaporation method without hole‐transport layer suffer from sulfur vacancy (VS) and a high back‐contact barrier. The same group anion exchange method demonstrates an efficient solution to fill VS and suppress the back‐contact barrier. However, the same group Te exchange with sulfur treatment has to implement at high temperature, which degrades the Sb2S3 film quality. Herein, a confined‐space selenium‐assisted tellurization (c‐SeTe) posttreatment strategy is developed to overcome aforementioned challenges. Material characterizations make certain that most tellurium is distributed at the back and there is a weak signal in bulk. Further physical characterizations unfold the c‐SeTe role in device performance. The back Se and Te alloying can suppress the back‐contact barrier to improve the extraction efficiency. And, Se and Te codoping in bulk helps to passivate the interface and bulk defects so as to improve the CdS/Sb2S3 heterojunction quality and enhance the long‐wavelength photon quantum yield. Finally, a champion power conversion efficiency of 4.95% is obtained, net 0.5% higher than the control one. The robust treatment method is expected to promote the fast development of antimony chalcogenide solar cells.

Water splitting with silicon p-i-n superlattices suspended in solution.

Photoelectrochemical (PEC) water splitting to produce hydrogen fuel was first reported 50 years ago1, yet artificial photosynthesis has not become a widespread technology. Although planar Si solar cells have become a ubiquitous electrical energy source economically competitive with fossil fuels, analogous PEC devices have not been realized, and standard Si p-type/n-type (p-n) junctions cannot be used for water splitting because the bandgap precludes the generation of the needed photovoltage. An alternative paradigm, the particle suspension reactor (PSR), forgoes the rigid design in favour of individual PEC particles suspended in solution, a potentially low-cost option compared with planar systems2,3. Here we report Si-based PSRs by synthesizing high-photovoltage multijunction Si nanowires (SiNWs) that are co-functionalized to catalytically split water. By encoding a p-type-intrinsic-n-type (p-i-n) superlattice within single SiNWs, tunable photovoltages exceeding 10 V were observed under 1 sun illumination. Spatioselective photoelectrodeposition of oxygen and hydrogen evolution co-catalysts enabled water splitting at infrared wavelengths up to approximately 1,050 nm, with the efficiency and spectral dependence of hydrogen generation dictated by thephotonic characteristics of the sub-wavelength-diameter SiNWs. Although initial energy conversion efficiencies are low, multijunction SiNWs bring the photonic advantages of a tunable, mesoscale geometry and the material advantages of Si-including the small bandgap and economies of scale-to the PSR design, providing a new approach for water-splitting reactors.

Stitching Perovskite Grains with Perhydropoly(Silazane) Anti‐Template‐Agent for High‐Efficiency and Stable Solar Cells Fabricated in Ambient Air

All inorganic CsPbI3perovskite solar cells (PSCs) have emerged as disruptive photovoltaic technology owing to their admirable photoelectric properties and the non‐volatile active layer. However, the phase instability against moisture severely limits the fabrication environment for the high‐efficiency devices, breaking through the confinement region to achieve scalable manufacturing has been the primary issue for future commercialization. Here, we develop a curing‐anti‐solvent strategy for fabricating high‐quality and stable black‐phase CsPbI3perovskite films in ambient air by introducing an inorganic polymer perhydropolysilazane (PHPS) into methyl acetate to form anti‐template agent. The cross‐linked PHPS reduces moisture erosions while the hydrolyzate silanol network (–Si(OH)4–) controls the perovskite crystal growth by forming Lewis adducts with PbI2during the fabrication. The polycondensation adduct of Si–O–Si/Si–O–Pb strongly binds to CsPbI3grains as a shield layer to hamper phase transition. Using the inorganic CsPbI3perovskite thin‐film with PHPS‐modified anti‐solvent processing as the light absorber, the n–i–p planar solar cell achieved an efficiency of 19.17% under standard illumination test conditions. More importantly, the devices showed excellent moisture stability, retaining about 90% of the initial efficiency after 1000 h under 30% RH.

Lead-free, formamidinium germanium-antimony halide (FA4GeSbCl12) double perovskite solar cells: the effects of band offsets.

Double halide perovskites have received massive attention due to their low toxicity, tunable bandgap, structural flexibility, and stability as compared to conventional 3D lead halide perovskites. Particularly, newly discovered formamidinium germanium-antimony halide (FA4GeSbCl12) double perovskites offer an excellent bandgap (∼1.3 eV) for solar cell (SC) applications. Therefore, in this study, for the first time, we have simulated FTO/TiO2/FA4GeSbCl12/Cu2O/Au planar SCs using SCAPS-1D, showing a maximum power conversion efficiency of 22.5% with Jsc = 34.52 mA cm-2, Voc = 0.76 V, and FF = 85.1%. The results show that the variation in valence and conduction band offsets (-0.4 to +0.2 eV and -0.4 to +0.57 eV) at the ETL/absorber and absorber/HTL interfaces dominate the SC performance. Also, different absorber defect densities (1 × 1014-1 × 1020 cm-3) and thicknesses (200-3000 nm) effectively influence the PCE. Moreover, simulated impedance spectroscopy (IS) data (through SCAPS-1D) were fitted using equivalent electrical circuits to extract relevant parameters, including Rs, RHF, and RLF, allowing us to better discuss the physics of the device. The fitted IS results strongly revealed that enhanced SC performance is associated with higher recombination resistance and a larger recombination lifetime. Likewise, a slight variation in the Rs (0 to 2.5 Ω cm2) highly impacts the PCE (22.5% to 19.7%). Furthermore, a tandem cell is designed by combining the top cell of ethylenediammonium-FASnI3 perovskite with the FA4GeSbCl12 bottom cell using a filtered spectrum strategy, which opens the door for multi-junction SC applications. These findings firmly reveal that the appropriate energy level alignment at interfaces with suitable material properties is the key to boosting SC performance.

Controlling of Conductivity and Morphological Properties of Hole-Transport Layer Using Ionic Liquid for Vacuum-Free Planar Hybrid Solar Cells

In this study, an acidic (A) and pH-neutral (pHN) solution using poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the hole-transport layer (HTL) was modified using a 1-butyl-3-methylimidazolium chloride (BMIM+Cl−) ionic liquid (IL). The effects of this ionic liquid on the conductivity and morphological properties of the PEDOT:PSS films were investigated. The conductivity and morphological properties of the PEDOT: PSS films before and after adding IL were measured using a UV–vis spectrophotometer and atomic force microscope (AFM), respectively. The conductivity of the A-PEDOT:PSS-film-based ionic liquid was decreased, while the conductivity of the pHN-PEDOT:PSS-film-based ionic liquid was increased. The surface morphology of the A-PEDOT:PSS-film-based ionic liquid was slightly decreased, while the conductivity of the pHN-PEDOT:PSS-film-based ionic liquid was slightly increased. The vacuum-free planar hybrid solar cells (VFPHSCs) using the pHN-PEDOT:PSS-film-based ionic liquid show a higher power conversion efficiency (PCE) than the VFPHSCs using the A-PEDOT:PSS-film-based ionic liquid. We also report that a solar cell with a structure of ITO/pHN-PEDOT:PSS/PTB7:PCBM/PEO/EGaIn has a maximum PCE of about ~5%.

Nitrogen-Doped Nickel Graphene Core Shell Synthesis: Structural, Morphological, and Chemical Composition for Planar Hybrid Solar Cells Application

In this study, nitrogen-doped nickel graphene core cells (N-NiGR) are synthesized using the thermal chemical vapor deposition method. The structural, morphological, and chemical composition properties of N-NiGR are investigated using X-ray diffractometry (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), respectively. N-NiGR has shown potential as a material that can assist charge carrier transportation in the photoactive a layer of planar hybrid solar cell (PHSC) owing to its high charge carrier mobility and stability with the solution process. Here, we investigated for the first time an enhancement of the solar cell efficiency (by up to a 2% increase) in PHSCs by incorporating the charge selective N-NiGR into the device’s photoactive layer. Synthesized N-NiGR with different concentrations are incorporated into the active layer of the devices as charge transport material. The device structure of an ITO-coated glass/Hole transport layer/(PBT7+N-NiGR+SnS)/Electron transport layer/Cathode is fabricated and the maximum power conversion efficiency of the device was observed to be about 4.35%.

A liquid medium annealing strategy for highly [041]/[141]-oriented planar antimony sulfide solar cells with 7.23% efficiency

Antimony sulfide (Sb2S3) is regarded as one of candidate materials for tandem top cells with silicon based solar cells due to its non-toxicity, appropriate bandgap, high absorption coefficient and good stability. However, restricted by the difficulty of carrier transportation caused by unfavorable orientations of Sb2S3, the power conversion efficiency (PCE) is still relatively low. In this work, a new annealing method, called liquid medium annealing (LMA), is developed to versatilely regulate the orientation of Sb2S3 films by controlling the concentration of Se22--OAm. Compared with conventional vapor-assisted annealing, a highly [041]/[141] oriented Sb2S3 film with unique title angles can be skillfully prepared by LMA with top-down model, which facilitates the photo-induced carrier separation along (Sb4S6)n ribbon. Meanwhile, such a LMA tactic can effectively tailor the band alignment at back contact by raises the valence band maximum (VBM) of Sb2S3, and then reducing hole collection barrier. Finally, a high PCE of 7.23% is achieved and considered the first echelon in planar Sb2S3 solar cells.

Achieving highly efficient and stable MAPbI3 planar solar cell by embedding Cs+, Fe2+, and Cd2+ metal inorganic cations in perovskite structure

Perovskite solar cells (PSCs) have been attracted the attention of many researchers due to their high conversion efficiency, low manufacturing cost, easy manufacturing steps, high light absorption, and the possibility of changing the photo electronic properties by modifying the chemical structure. Despite the mentioned advantages, the low stability of PSCs and toxicity of lead in the perovskite layer were the challenging issues in this field. In this regard, the use of mixed cation and mixed halide perovskite compounds with high crystal quality, efficiency, and stability has attracted enormous attention. In this project, Fe2+, Cd2+, and Cs+ cations with various contents (Fe2+ + Cd2+: 5% and 10%; Cs+: 5% and 10%) were partially replaced the Pb2+ and CH3NH3+ cations, respectively in the MAPbI3 perovskite structure through a two-step process using spin-coating. The as-synthesized [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 5, 10%, y: 5, 10%) perovskites were characterized with X-ray diffraction (XRD), grazing incidence X-ray diffraction (GIXRD), and field emission scanning electron microscopy (FESEM). The optical properties of prepared compounds were investigated by ultraviolet–visible (UV–Vis) and photoluminescence (PL) spectroscopy. The photovoltaic behavior as well as stability of solar cells containing MAPbI3, [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 5%, y: 5%), and [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 10%, y: 10%) perovskites as active layers were evaluated by current density-voltage (I–V) under AM1.5G illumination.Results showed that partial substitution of CH3NH3+ cations with Cs+ and Pb2+ cations with Fe2+ + Cd2+ in the CH3NH3PbI3 structure improved crystallinity and photovoltaic parameters. The average power conversion efficiency (PCE) of six solar cell containing [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 10%, y: 10%) perovskite layer was 21.04% which was 1.03 and 1.21 times higher than that cells containing [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a], (a+b): 5%, y: 5%) and MAPbI3, respectively.The electrochemical impedance spectroscopy (EIS) was utilized to study the charge transfer resistance (Rct) and recombination resistance (Rrec) of prepared solar cells. The Rct and Rrec values of fabricated solar cell were decreased and increased, respectively in the presence of Fe2+, Cd2+, and Cs+ inorganic cations. As a result, the [CsyMA1-yPb1-a-bFeaCdbI3-2aCl2a] perovskites can be considered as the appropriate candidate with high efficiency, stability, and low lead content in the planar perovskite solar cells.

Additive strategy to regulate crystallization and charge carrier dynamics of CsBi3I10 towards efficient and stable thin film solar cells

All-inorganic semiconductor CsBi3I10 (CBI) has recently been recognized as promising alternatives to lead-based light harvesting materials. However, poor film quality and high defects greatly limit its photovoltaic performance in solar cell applications. Here, a simple and effective multifunctional additive of lead thiocyanate (Pb(SCN)2) is doped into CBI for tailoring film morphology and optoelectronic properties. Synergistic effects of Pb2+ and pseudohalide SCN- enable fine regulation of CBI crystallization as well as defects passivation, resulting in the formation of high-quality thin film with desirable uniformity, negligible pinholes, high electrical conductivity and remarkable moisture tolerance. The additive Pb(SCN)2 can efficiently alleviate moisture-induced degradation mechanism by inhibiting the phase transition from CBI to Cs3Bi2I9. In addition, the resulting solar cells exhibit significantly enhanced carrier lifetime, reduced charge recombination and increased charge collection yield, leading to a record efficiency of 1.13 % for planar CBI-based thin film solar cells. This work suggests additive engineering is efficient to modulate film properties and solar cell performance, which could be generally applicable to fabricate other Bi-based thin film and optoelectronic devices.

A Codoping Strategy for Efficient Planar Heterojunction Sb2S3 Solar Cells

AbstractAntimony sulfide is a promising wide bandgap light‐harvesting material owing to its high absorption coefficient, nontoxicity, superior stability, and low cost. However, the reported Sb2S3 absorber suffers from complicated defect characteristics due to its quasi‐1D structure. Herein, a codoping technique from chlorine and selenium is developed in hydrothermal method to regulate the film defect properties and promote the device efficiency. The theoretical calculation and experimental results demonstrate that the Cl&Se codoping plays a synergistic role in absorber film quality improvement. Se doping could efficiently fill the intrinsic deep defect level VS and Cl is a benign n‐type dopant and favor [hk1] oriented deposition. Systematic device physical characterizations verify the codoped device superior heterojunction quality and much lower interface and bulk defect density comparing with control one. The optimal codoping device delivers a certified power conversion efficiency of 7.15% (5.9% for control one), the highest certified value in planar Sb2S3 solar cells. This study develops an effective doping strategy with multi‐element synergistic incorporation which sheds new light on high‐efficiency Sb2S3 solar cells.

Performance of planar perovskite solar cells based on formamidinium cations: Simulation and fabrication

The best efficiency ever recorded for state-of-the-art perovskite solar cells (PSCs) is about 25% where the formamidinium (FA)-dominated perovskites were adopted. But the optimum content of FA perovskite solar cells based on Cs0.05(FAxMA[1−x])0.95Pb(I0.83Br0.17)3 films has yet to materialize the high-power conversion efficiency. Herein, high quality and uniform perovskite films constituting Cs-MA-FA (Cesium; Methylammonium) mixed cation in the A-site of the ABX3 structure with different FA content are synthesized by a typical spin coating based antisolvent technique. Because of the limitations of perovskite and solar cell materials, the influences of various FAs on the device performance are analyzed through device simulation. From the synthesized films, the band gap equation of Cs0.05(FAxMA[1−x])0.95Pb(I0.83Br0.17)3 has been estimated, ranging from 2.175 eV to 1.5 eV for various FA/(FA + MA) ratios respectively. Ultimately, the highest conversion efficiency of the planar solar cell based on graded perovskite with various FA content was obtained for the case where the positive Eg grading consists of the Eg of 2.175 eV at the front (FA/[FA + MA] of 0) and the Eg of 1.5 eV at the back (FA/[FA + MA] of 1). The Cs0.05(FA0.87MA0.13)0.95Pb(I0.83Br0.17)3 cell achieved an AM1.5G conversion efficiency of around 20.98%, showing improved VOC, JSC, and FF among the planar perovskite solar cells with different x.

Boosting photovoltaic performance for Sb2S3 solar cells by ionic liquid-assisted hydrothermal synthesis

Bulk and surface trap-states in the Sb2S3 films are considered one of the crucial energy loss mechanisms for achieving high photovoltaic performance in planar Sb2S3 solar cells. Because ionic liquid additives offer interesting physicochemical properties to control the synthesis of inorganic material, in this work we propose the addition of 1-Butyl-3-methylimidazolium hydrogen sulfate (BMIMHS) into a Sb2S3 hydrothermal precursor solution as a facile way to fabricate low-defect Sb2S3 solar cells. Lower presence of small particles on the surface, as well as higher crystallinity are demonstrated in the BMIMHS-assisted Sb2S3 films. Moreover, analyses of dark current density-voltage J–V curves, surface photovoltage transient and intensity-modulated photocurrent spectroscopy have suggested that adding BMIMHS results in high-quality Sb2S3 films and a successful defect passivation. Consequently, the best-performing BMIMHS-assisted device exhibits a 15.4% power conversion efficiency enhancement compared to that of control device. These findings show that ionic liquid BMIMHS can effectively be used to obtain high-quality Sb2S3 films with low-defects and improved optoelectronic properties.