Heterojunction Solar Cells Research Articles

The effect of the curing process on illuminated annealing of silicon heterojunction solar cells

The effect of the curing process on illuminated annealing of silicon heterojunction solar cells

Interfacial Band Engineering of Highly Efficient PEDOT:PSS/p‐Si/ZnO Heterojunction Solar Cells

Hybrid heterojunction solar cells (HHSCs) using different active materials as hole‐selective transport layers and electron‐selective transport layers show great potential in both low cost and high power conversion efficiency (PCE). Herein, PEDOT:PSS/p‐Si/ZnO backcontact heterojunction solar cells are prepared using the simple low‐temperature solution method. PEDOT:PSS is introduced into p‐Si‐based solar cells as an antireflective and passivation layer to optimize device performance. The effect of the work function (WF) of ZnO on device performance is investigated, and a PCE of 10.74% is achieved using low‐WF ZnO. In addition, the PEDOT:PSS layer is doped with Nafion, and the surface passivation quality of the p‐Si is dramatically enhanced. By optimizing the doping concentration of Nafion, the PCE of the optimized device reaches 11.43%, which is currently the highest PCE for p‐Si‐based solar cells using solution method. The findings provide a simple and promising method to achieve high‐performance PEDOT:PSS/p‐Si/ZnO HHSCs.

A Review on Self-Assembly Driven Optoelectronic Properties of Polythiophene-Peptide and Polythiophene-Polymer Conjugates.

Polythiophene (PT) is an important conducting polymer for its outstanding optoelectronic properties. Here, we delineate the self-assembly-driven optoelectronic properties of PT-peptide and PT-polymer conjugates, taking examples from recent literature reports. PT-peptide conjugates made by both covalent and noncovalent approaches are discussed. Poly(3-thiophene acetic acid) (P3TAA) covalently coupled with Gly-Gly-His tripeptide, C-protected and deprotected tripeptide H2N-F-F-V-OMe, etc. exhibits self-assembly-driven absorbance, fluorescence, photocurrent, and electronic properties. Noncovalent PT-peptide conjugates produced via ionic, H-bonding, and π-stacking interactions show tunable morphology and optoelectronic properties by varying the composition of a component. PT conjugated with Alzheimer's disease peptide (KLVFFAE, Aβ16-22) shows enhanced photocatalytic water splitting, cationic PT(CPT-I)-perylene bisimide-appended dipeptide (PBI-DY), and anionic PT-perylene diimide-appended cationic peptide (PBI-NH3+) conjugates and exhibits self-assembly-driven enhanced photoswitching and organic mixed electronic and ionic conductivity (OMEIC) properties. In the PT-polymer conjugates, self-assembly-driven optoelectronic properties of covalently produced PT-random copolymers, PT-block copolymers, PT-graft-random copolymers, and PT-graft-block copolymer conjugates are discussed. The HOMO-LUMO levels of hyperbranched polymers are optimized to obtain better power conversion efficiency (PCE) in the bulk heterojunction (BHJ) solar cell than in linear polymers, and P3TAA-ran-P3HT (43 mol % P3TAA) conjugated with MAPbI3 perovskite exhibits higher PCE (10%) than that with only P3TAA hole-transporting material. In the ampholytic polythiophene (APT), on increasing pH, the morphology changes from the vesicle to fibrillar network for the dethreading of the PT chain, resulting in a red shift of the absorbance peak, an enormous increase in PL intensity, lowering of the charge transfer resistance, and an induction of Warburg impedance for the release of quencher I- ions. The PT-g-(PDMAEMA-co-PGLU-HEM) graft copolymer self-assembles with Con-A lectin, causing fluorescence quenching, and acts as a sensor for Con-A with a LOD of 57 mg/L. Varying sequences of the block copolymer containing pH-responsive PDMAEMA and temperature-responsive PDEGMEM grafted to the PT backbone shows different self-assembly, optical, electronic, and photocurrent properties depending on the proximity and preponderance of the block sequence on the PT backbone.

Towards a cutting‐edge metallization process for silicon heterojunction solar cells with very low silver laydown

AbstractWithin this work, we investigate the potential to optimize the screen‐printed front side metallization of silicon heterojunction (SHJ) solar cells. Three iterative experiments are conducted to evaluate the impact of the utilized fine mesh screen configurations and grid layout adaption (finger pitch) for the front side metallization on silver laydown and electrical performance of the solar cells. With respect to the screen configuration, we compare the performance of a fine‐mesh knotless screen to a conventionally angled screen demonstrating an additional gain of Δη = +0.1%abs due to reduced shading losses. Additionally, a grid layout is improved by increasing the number of contact fingers from 120 to 156. Furthermore, the current possibility to push the fine‐line printing process for low‐temperature pastes to the limit is investigated by reducing the nominal finger width wn to 20, 18, and 15 μm. It is shown that even the smallest nominal width of wn = 15 μm can be printed with high quality, leading to an additional efficiency gain of Δη = +0.15%abs as well as a reduction of silver paste laydown by −5 mg. Finally, a batch of champion cells is fabricated by applying the findings of the previous experiments, which results in a maximum efficiency of ηmax = 23.2%. Compared to the reference group without optimization, this corresponds to a gain of Δη = +0.17%abs, which comes along with an additional decrease of the silver paste laydown by approximately −2 mg. This emphasizes the significance of consistent optimization of the screen‐printing process in terms of cell performance and resource utilization for SHJ solar cells.

Interdigitated‐back‐contacted silicon heterojunction solar cells featuring novel MoOx‐based contact stacks

AbstractThe fabrication process of interdigitated‐back‐contacted silicon heterojunction (IBC‐SHJ) solar cells has been significantly simplified with the development of the so‐called tunnel‐IBC architecture. This architecture utilizes a highly conductive (p)‐type nanocrystalline silicon (nc‐Si:H) layer deposited over the full substrate area comprising pre‐patterned (n)‐type nc‐Si:H fingers. In this context, the (p)‐type nc‐Si:H layer is referred to as blanket layer. As both electrodes are connected to the same blanket layer, the high lateral conductivity of (p)nc‐Si:H layer can potentially lead to relatively low shunt resistance in the device, thus limiting the performance of such solar cells. To overcome such limitation, we introduce a thin (<2 nm) full‐area molybdenum oxide (MoOx) layer as an alternative to the (p)nc‐Si:H blanket layer. We demonstrate that the use of such a thin MoOx minimizes the shunting losses thanks to its low lateral conductivity while preserving the simplified fabrication process. In this process, a novel (n)‐type nc‐Si:H/MoOx electron collection contact stack is implemented within the proposed solar cell architecture. We assess its transport mechanisms via electrical simulations showing that electron transport, unlike in the case of tunnel‐IBC, occurs in the conduction band fully. Moreover, the proposed contact stack is evaluated in terms of contact resistivity and integrated into a proof‐of‐concept front/back‐contacted (FBC) SHJ solar cells. Contact resistivity as low as 100 mΩcm2 is achieved, and fabricated FBC‐SHJ solar cells obtain a fill factor above 81.5% and open‐circuit voltage above 705 mV. Lastly, the IBC‐SHJ solar cells featuring the MoOx blanket layer are fabricated, exhibiting efficiencies up to 21.14% with high shunt resistances above 150 kΩcm2. Further optimizations in terms of layer properties and fabrication process are proposed to improve device performance and realize the efficiency potential of our novel IBC‐SHJ solar cell architecture.

Solution Processing Silicon Heterojunction Photocathode for Efficient and Stable Hydrogen Production.

Efficient and stable photocathodes are crucial for the development of photoelectrochemical (PEC) water-splitting devices. Silicon heterojunction (SHJ) solar cell is one of the most advanced photovoltaic cells. However, due to the instability of its outermost indium tin oxide (ITO) layers in the electrolyte, a protective layer needs to be introduced on its surface. Previously reported high-quality protective layers almost all involved the use of expensive thin film manufacturing techniques such as atomic layer deposition (ALD). In this work, for the first time, a new strategy is proposed of modifying SHJ-based photocathode with yttrium hydroxide (Y(OH)3) through two-step solution methods to simultaneously improve the stability and activity. The optimized SHJ photocathode exhibits a high applied bias photon-to-current efficiency (ABPE) of 8.4% under simulated 100mWcm-2 (1 Sun) with an AM 1.5G filter in 0.5m KOH. Furthermore, the obtained SHJ photocathode demonstrates excellent stability of at least 110h at 0.3V versus RHE. In this work, combining facile direct current magnetron sputtering with a solution treatment technique provides a novel design strategy, which lowers the threshold for preparing high-quality protective layer, and paves the way for developing economic, efficient, and stable SHJ-based PEC devices.

Synthesis of 1,4‐dihydropyrrolo[3,2‐b]pyrrole‐containing donor–acceptor copolymers and their optoelectronic properties

AbstractDonor–acceptor (D–A)‐conjugated polymers have achieved promising performance metrics in numerous optoelectronic applications that continue to motivate studying structure–property relationships and discovering new materials. Here, the materials toolbox is expanded by synthesizing D–A copolymers where 1,4‐dihydropyrrolo[3,2‐b]pyrrole (DHPP) is directly incorporated into the main chain of D–A copolymers for the first time via direct heteroarylation polymerization. Notably, the synthetic complexity of DHPP‐containing polymers coupled with thieno[3,2‐b]pyrrole‐4,6‐dione (TPD) or 3,6‐bis(2‐thienyl)‐2,5‐dihydropyrrolo[3,4‐c]pyrrole‐1,4‐dione (Th2DPP) comonomers is calculated to be lower compared to many common conjugated polymers synthesized via direct arylation. The electron‐rich nature of DHPPs when coupled with TPD or DPP enables optoelectronic properties to be manipulated, evident by measuring distinctly different absorbance and redox properties. Additionally, these D–A copolymers demonstrate their potential in organic electronic applications, such as electrochromics and organic photovoltaics. The reported DHPP‐alt‐Th2DPP copolymer is the first DHPP‐based colored‐to‐transmissive electrochrome and achieves power conversion efficiencies of ~2.5% when incorporated into bulk heterojunction solar cells. Overall, the synthetic accessibility of DHPP monomers and their propensity to participate in robust polymerizations highlights the value of establishing structure–property relationships of an underutilized scaffold. These fundamental attributes serve to inform and advance efforts in the development of DHPP‐containing copolymers for various applications.

Exploring the potential of tin-based perovskite-silicon tandem solar cells through numerical analysis: A pathway to sustainable energy innovation

“Necessity is the mother of invention.” The global imperative to transition from fossil fuels to renewable energy sources, driven by the pressing issue of climate change, highlights the significance of advancing solar energy technologies. While single junction solar cells have reached a peak efficiency of approximately 31 %, the pursuit of higher efficiency has led to the exploration of tandem solar cell architectures, including perovskite-silicon and all-perovskite configurations. However, the widespread use of lead in perovskite structures raises environmental and health concerns. In response to these challenges, this study proposes a novel approach by integrating a tin-based wide bandgap absorber layer with a silicon HIT solar cell (Heterojunction with Intrinsic Layer). The investigation consists of an extensive exploration of six different carrier transport layers (CTL) for the top perovskite layer, considering variations in thickness and defect density. A comprehensive analysis of charge carrier dynamics within the device is conducted to understand the role of defect density in influencing solar cell performance parameters. Simulation results show that the overall tandem device gives an encouraging PCE of 32.12 % in 2 T configuration due to its excellent high value of current density matching 17.63 mA/cm2 and open-circuit voltage of 2.19V. We sincerely hope that our work will open new avenues in the field of Solar Photovoltaics paving the way for future innovations.

Effect of nucleating agents on crystalline silicon textured structure: From upright pyramid to analogous inverted pyramid

For further improving the efficiency of solar cells, it is one of the mainstream approaches to obtain a novel textured surface structure with lower reflectivity, without affecting the existing industry processes. However, the current rapid texturing methods used in the industry can only achieve an upright pyramid structure. This study first analyzed how the rapid texturing process is achieved through texturing additives. Subsequently, based on this principle, we investigated the core component of the texturing additives—nucleating agent—and examined how its concentration influences the surface structure, leading to the development of an analogous inverted pyramid structure with advantageous reflectivity. To remove the damage layer generated at the top edges of the analogous inverted pyramid due to insufficient etching, a two-step texturing process was proposed. This process aims to protect the structure while effectively removing the damage layer. Ultimately, we applied the two-step texturing process to fabricate heterojunction solar cells with the analogous inverted pyramid textured surface, achieving an efficiency of 25.43 %, which is 0.19 % higher than conventional upright pyramid structure cells.

Bulk Heterojunction Solar Cell using Ru Dye Attached PCBM

Ru dye (Z-907) is a crucial photosensitizing material in dye-sensitized solar cells (DSSCs). To enhance the utilization of Ru dye’s photosensitizing properties in bulk heterojunction solar cells, a method was developed to synthesize phenyl-C61- butyric acid methyl ester (PCBM) nanoparticles that are chemically linked to Ru dye. PCBM contains a methoxy (−OCH3) group, whereas Ru dye incorporates a carboxyl group (−COOH) within its molecular structure. By exploiting these complementary functional groups, a successful bond between Ru dye and PCBM was established through an anhydride functional group. The coupling of PCBM with Ru dye results in a modification of the energy levels, yielding lower LUMO (3.8 eV) and HOMO (6.1 eV) levels, compared with the LUMO (3.0 eV) and HOMO (5.2 eV) levels of Ru dye alone. This configuration potentially facilitates efficient electron transfer from Ru dye to PCBM, alongside promoting hole transfer from Ru dye to the conducting polymer. Consequently, the bulk heterojunction solar cells incorporating this Ru dye-PCBM configuration demonstrate superior performance, with an open circuit voltage (Voc) of 0.62 V, short circuit current (Jsc) of 0.63 mA cm−2, fill factor (FF) of 65.6%, and a photovoltaic conversion efficiency (η) of 0.25%.

A simulation of the photoconversion efficiency of P3HT:PCBM bulk heterojunction: An insight on the charge collection efficiency

In organic bulk heterojunction solar cells, the internal quantum efficiency can be considered as the product of the absorption efficiency, the exciton diffusion efficiency, the charge transfer efficiency, and the charge collection efficiency. In previous studies, it has been reported that charge transfer and charge collection is very high in these solar cells, approaching 100 %. With a Monte Carlo simulation approach that considers the hopping of charges within the two materials of the heterojunctions, it is highlighted that an estimate of the charge collection efficiency can be evaluated considering that a certain number of charges do not reach the electrodes because of the random arrangement of the two materials in the heterojunction. The case of P3HT:PCBM (1:1 ratio) has been analyzed in this study.

A novel design and optimization of Si based high performance double absorber heterojunction solar cell

Researchers are currently focusing on Silicon (Si)-based solar cells due to their outstanding semiconductor properties. This study aims to enhance the performance of a new Si based solar cell structure of Cu/FTO/CdS/Si/FeSi2/Au and investigate how the inclusion of FeSi2 as a second absorber and CdS buffer layers affects key performance metrics such as VOC, JSC, FF, and PCE using SCAPS-1D simulation. Various factors including thickness, carrier concentration, defect density, temperature, and electrode design were analyzed in detail to improve performance. The PCE, VOC, JSC, and FF have shown 25.2 %, 0.718 V, 43.3 mA/cm2, and 80.8 %, respectively with reference structure's (Cu/FTO/CdS/Si/Au). The PCE, VOC, JSC, and FF have improved to 27.73 %, 0.74 V, 45.55 mA/cm2, and 79.94 %, respectively by adding FeSi2 layer as a bottom absorber with proposed structures (Cu/FTO/CdS/Si/FeSi2/Au). This research has the potential to offer insights and strategies for the development of cost-effective Si-based thin-film solar cells in a near future.

Structural optimization and growth of intrinsic hydrogenated amorphous silicon films by HWCVD

Although the silicon heterojunction (SHJ) solar cell is the crystalline silicon solar cell with highest conversion efficiency at present, its higher cost of production line has been a factor restricting its industrial development. The use of hot wire chemical vapor deposition (HWCVD) technology instead of the mainstream plasma enhanced chemical vapor deposition (PECVD) technology for the deposition of amorphous silicon films can effectively reduce the cost of equipment and processing, and has a bright future. In recent years, i-a-Si:H films grown by PECVD have obtained great improvement in passivation quality, whereas HWCVD technology has been neglected in this field. This has significantly limited the development and application of HWCVD technology in SHJ cell production. In this work, we exploited the differences in the films properties and microstructures deposited by various hot-wire temperatures and successfully developed a structure for the high-passivation-quality i-a-Si:H film grown by HWCVD, consisting of a buffer layer and a double-layer bulk stack. By introducing the buffer layer grown with the 1650 °C hot-wire temperature and pure silane, the effective minority carrier lifetime was improved from 2.3 ms to 7.5 ms, and a cell efficiency enhancement of 0.4%abs was obtained. By depositing the bulk layer sequentially with hot-wire temperatures of 1800 °C and 1900 °C, the passivation quality and the conductance were both improved. An effective minority carrier lifetime of 8 ms and a further cell efficiency enhancement of 0.15%abs were obtained. Finally, SHJ solar cell efficiency of 24.35% was obtained with a home-made HWCVD-based pilot SHJ cell line.

Modeling of Photovoltaic Characteristics of a TiO<sub>2</sub>/Porous-Si/Si-Based Heterojunction Solar Cell

This work is focused on the study of photosensitive structures based on porous Si and film TiO2, which are promising for solar energy. For numerical simulation of the transportation and accumulation of charge carriers in the considered heterostructure, the drift-diffusion approximation of the semiclassical approach was proposed. A device scheme of a solar cell model based on TiO2/porous-Si/Si heterostructures is proposed. Production of photoconverters of solar cells based on the TiO2/porous-Si/Si heterostructure can be carried out according to the standard method supplemented by additional technological operations. Ohmic contacts are formed in the upper and lower parts of the structure above the TiO2 and Si layers. The strip system of contacts is a contact grid, with hatching, the surface coefficient should not exceed 5%. The thickness of the applied layer of photoresist should be 1 μm. Using the PC1D program, the light characteristics of the fabricated structure were calculated (open circuit voltage VOC, short circuit current ISC, fill factor FF and efficiency η), and current-voltage characteristics were plotted. The influence of the thickness and doping level Nd and Na of porous Si and TiO2 layers on the productivity of a heterojunction solar cell TiO2/porous-Si/Si was studied in order to obtain a device with a good conversion efficiency. It was found that the energy conversion efficiency of a TiO2/porous-Si/Si solar cell can reach 22.5 %. Based on the optimized simulation conditions, it was found that the maximum solar cell efficiency is achieved at thicknesses of 100 and 200 nm and donor concentration of Nd=1∙1017 cm-3 and acceptor concentration of Na=1∙1018 cm-3 for TiO2 and porous Si buffer layer, accordingly.

Computational analysis of ligand design for Ru half-sandwich sensitizers in bulk heterojunction (BHJ) solar cells: Exploring the role of –NO2 group position and π-conjugation in optimizing efficiency

Bulk Heterojunction (BHJ) solar cells offer cost-effective photovoltaic solutions, flexible manufacturing, and improved efficiency with reduced environmental impact. Organometallic half-sandwich complexes, specifically a series of monometallic ruthenium complexes (Ru(1)–Ru(6)), have emerged as promising candidates for BHJ solar cells due to their outstanding charge transport properties. This study utilised Density Functional Theory (DFT) calculations with the B3LYP functional and SDD basis set augmented with 6-31 + G(d,p) to assess these Ru complexes with various N,O-chelating ligands, featuring distinct π-conjugated systems and positions of nitro groups, for BHJ solar cell applications. Our investigation focused on elucidating their electronic structures, identifying key electrophilic and nucleophilic sites, and exploring their optical properties. Our findings indicate that these complexes have maximum absorption wavelengths (λmax) ranging from 702 to 1083 nm, highlighting their strong photon absorption capabilities. Specifically, Ru(6), which includes the NO2 group, exhibits the narrowest energy gap but shows relatively lower values for oscillator strengths (f) and light harvesting efficiencies (LHE), indicating efficient light absorption but reduced energy conversion efficiency. In contrast, Ru(3), lacking the NO2 group but featuring enhanced π conjugation through cyclisation, demonstrates the widest energy gap yet boasts the highest values for f and LHE, suggesting superior efficiency in converting absorbed energy into electronic energy. These results emphasise the crucial role of ligand π-conjugation in enhancing energy conversion efficiency, while the strategic positioning of the NO2 group aids effective light absorption. Our study offers valuable insights into the design principles for optimizing organometallic ruthenium complexes in BHJ solar cell applications.

Study on the process of hydrogen-doped indium oxide for silicon heterojunction solar cell mass production

In this work, we conducted a comparative study on water vapor (H2O) process and hydrogen gas (H2) process to prepare the IMO:H films based on industrialized DC magnetron sputtering system. To dynamically control the residual H2O pressure, we installed a set of polycold coil and kept it turned on during the sputtering process. The film characteristics of Hall mobility, carrier density, sheet resistance, and transparency was investigated. The results revealed that the silicon heterojunction (SHJ) solar cell with H2 process had a higher Hall mobility and greater transparency in the 400–600 nm wavelength range resulting in a lower contact resistivity and a slight increase current density compared to the H2O process. The median efficiency (Eff) achieved with the H2 process improved by 0.09% absolute to 25.43%, mainly because of the increased Jsc and FF. And the IMO:H films with H2 process had a large basal spacing with (400) and (222) crystal planes resulting in maintaining a more stable and reliable structure at temperatures below 200 °C. After the optimization of TCO layer process, we manufactured the industrial-grade SHJ cells with max efficiency (Eff), Voc, Jsc, and fill factor (FF) values as high as 26.27%, 753 mV, 41 mA/cm2, and 86%, respectively. The IMO:H films with H2 process can thus be considered more suitable for large-scale production.

Study on the Thermal Stability of Molybdenum Oxide‐Passivated Silicon Solar Cells

Dopant‐free heterojunction (HJ) solar cells are known for their simple process conditions and low parasitic absorption. However, stability issues remain one of the major obstacles for further development of cells with transition metal oxides (TMOs). Therefore, this research demonstrates the mechanism of thermal annealing degradation effects on TMOs/silicon (Si) HJ, namely, the infiltration of oxygen from air and the bidirectional diffusion of oxygen from TMOs, by investigating a typical molybdenum oxide (MoOx)/Si contact. A dense Au interlayer is introduced to block the interdiffusion of oxygen from the MoOx/Si interface and its surrounding environment. As a result, the dense layer slows down the interfacial oxidation of MoOx/Si and the degradation of the MoOx work function, thus improving the stability of the MoOx/Si HJ to 200 °C. The diffusion of oxygen from MoOx to the MoOx/Si interface will be critical to further promote the thermal stability of the devices thereafter, especially for the cells with i‐a‐Si:H layer as the passivation layer. To attain stable dopant‐free cells with MoOx, it is crucial to prevent oxygen diffusion into Si while maintaining a high MoOx work function and a thin SiOx layer at the interface.

Numerical simulation based performance enhancement approach for an inorganic BaZrS3/CuO heterojunction solar cell

One of the main components of the worldwide transition to sustainable energy is solar cells, usually referred to as photovoltaics. By converting sunlight into power, they lessen their reliance on fossil fuels and the release of greenhouse gases. Because solar cells are decentralized, distributed energy systems may be developed, which increases the efficiency of the cells. Chalcogenide perovskites have drawn interest due to their potential in solar energy conversion since they provide distinctive optoelectronic characteristics and stability. But high temperatures and lengthy reaction periods make it difficult to synthesise and process them. Therefore, we present the inaugural numerical simulation using SCAPS-1D for emerging inorganic BaZrS3/CuO heterojunction solar cells. This study delves into the behaviour of diverse parameters in photovoltaic devices, encompassing efficiency (η) values, short-circuit current density (Jsc), fill factor (FF), and open-circuit voltage (Voc). Additionally, we thoroughly examine the impact of window and absorber layer thickness, carrier concentration, and bandgap on the fundamental characteristics of solar cells. Our findings showcase the attainment of the highest efficiency (η) values, reaching 27.3% for our modelled devices, accompanied by Jsc values of 40.5 mA/cm2, Voc value of 0.79 V, and FF value of 85.2. The efficiency (η) values are chiefly influenced by the combined effects of Voc, Jsc, and FF values. This optimal efficiency was achieved with CuO thickness, band gap, and carrier concentration set at 5 µm, 1.05 eV, and above 1019 cm−3, respectively. In comparison, the optimal parameters for BaZrS3 include a thickness of 1 µm, a carrier concentration below 1020 cm−3, and a band gap less than 1.6 eV. Therefore, in the near future, the present simulation will simultaneously provide up an entirely novel field for the less defective perovskite solar cell.

Influence of Magnesium Doping Concentrations and annealing on the Transmittance and Energy Band-gap of Sb2S3 Thin Films Deposited via Chemical Bath Deposition Technique

The incorporation of thin film materials into a wide range of technological applications has attracted considerable interest owing to their distinct properties and versatile functionalities. In this study, Magnesium alloyed and Antimony sulphide (Sb2S3) thin films were successfully deposited on glass substrates by chemical bath deposition technique. The films were grown at room temperature of constant pH. The concentrations of magnesium varied between 0.1M and 0.3M. The films were annealed at annealing temperature between 100˚C and 300˚C at a fixed annealing time of 1 hour. The films were characterized using UV-spectrophotometer to investigate the variation of optical and solid state properties with wavelength in the UV-VIS-NIR region. The result showed that the presence of the alloying agent and annealing treatments modified the optical and solid state properties of the films significantly. The transmittance of the films was high. Annealing led to reduced transmittance due to increased crystallite size, notably in films doped with 0.1M Mg2+ ions and annealed at 200˚C, suggesting enhanced photon absorption. The energy band gaps were found to be direct and in the range of 1.25 eV to 1.72 eV for the as grown films and 1.15eV to 1.3eV for the films annealed at annealing temperatures 300˚C. The study identifies a direct correlation between magnesium doping concentration, annealing conditions, and shifts in the energy band-gap of the films. The values of the energy band gaps are all within the range suitable for use of the layers as absorbers in hetero-junction solar cell devices for sustainable energy applications.

Synergetic Effect of Gas Compositions on Material Properties of n‐Type Nanocrystalline Silicon Oxide Prepared by Plasma‐Enhanced Chemical Vapor Deposition

Hydrogenated nanocrystalline silicon oxide (nc‐SiOx:H) has drawn extensive attention during the past years for the utilization of silicon heterojunction (SHJ) solar cells. This material is demonstrated to be the key to the performance improvement of SHJ solar cells. Herein, the influence of the process gas compositions on the optical, electronic, chemical, and structural properties of n‐type nc‐SiOx:H films at the thickness of 38 nm is systematically investigated. The synergetic effect of CO2 and PH3 gas flow fraction ( and ) and the synergetic effect of CO2 and SiH4 gas flow fraction ( and ) on the growth of nc‐SiOx:H (n) films are demonstrated. Creatively combining the Fourier‐transform infrared, UV‐Raman scattering spectroscopy, spectroscopy ellipsometry, and photo‐thermal deflection spectroscopy measurement, the mechanism behind the synergetic effect of the gas compositions on the material properties is analyzed.