Doped Layer Research Articles

Effect of PANI-Doped-Graphene Oxide as HTL in Perovskite Solar Cells Using SCAPS-1D Software

This research examines and analyses the solar cell performance of methylammonium lead triiodide (MAPbI3) perovskite solar cells (PSC) that utilize Polyaniline (PANI)-doped-graphene oxide (GO) as HTL. Additionally, the study used the SCAPS-1D simulation software to model and analyze the experimental data. The simulated data generated by the SCAPS-1D software is afterward compared to the experimental findings. This comparison serves as a foundation for further optimization of the solar cell's performance. This study explicitly examined the impact of layer thickness and doping density on device performance in order to determine which parameters should be optimized to enhance overall performance. The SCAPS-1D simulation obtained a highest power conversion efficiency (PCE) of 15.37%. This work presented an improved efficiency of 40% from the experimental data. The findings of our study have the potential to be used in the prediction of key parameters for the optimization of perovskite solar cells (PSCs) using doped PANI/GO as a hole transport layer (HTL).

Photoelectric-coupled multilayer smart glass synergistically regulated with doped nanoparticles of GaAs and IST phase change layers

Windows are the main part of the building energy exchange. Most of the solar energy that passes through the windows is reflected or converted into heat loss, which causes a great waste of energy. To improve the energy utilization, this work presents the design of a multilayer glass with a GaAs layer doped by nanoparticles and an IST (In3SbTe2) phase change layer. The dielectric function of the doped layer is obtained by the Maxwell-Garnett effective medium theory. The transmittance and the photoelectric conversion efficiency are calculated through the transfer matrix method. With the genetic algorithm, the structure parameters are optimized to achieve the high values of both average transmittance in human-eye response band and photoelectric conversion energy. The average transmittance of the human eye response band for the structure containing only GaAs doped layer reaches 0.5–0.6, and the average photovoltaic conversion efficiency is above 0.2. After adding the IST phase change layer, the difference of ranges of the spectral regulation between the two phases in the metal nanoparticle doped structure can reach more than 0.25. The light transmission regulation is realized by active phase change. This work provides an optimization-based analysis approach and a possible design of the multilayer smart glass.

Electronic vs optical bandgap of stoichiometric V2O5: Effects of surface transfer doping and electron accumulation layer

The experimental and theoretical bandgap reported for stoichiometric V2O5, a layered semiconductor of great technological importance, spans a wide range of 1.7–4.8 eV. Using combined photoemission, absorption, and photoluminescence measurements, we show that the fundamental electronic gap of V2O5 is 1.85 eV, which is in close agreement with the value of 1.8 eV predicted by the first density functional theory studies, but is lower than the value of 2.2–2.8 eV obtained from optical absorption and photoemission studies. It is shown that this difference between the fundamental and optical gaps is due to the presence of a surface electron accumulation layer, which results in a Burstein–Moss shift of the Fermi level well into the conduction band. The underlying cause of degenerate electron doping is due to “surface transfer doping” by ambient water molecules as a result of the high electron affinity of the semiconductor.

Effect of Al doping on structural and electrical properties of HfO2/ZrO2 layered structures for high-k applications

ZrO2 films with ultrathin Al2O3 layers have effectively contributed to the miniaturization of dynamic random access memory (DRAM) capacitors for many years. However, as memory devices continue to shrink, higher dielectric constants are required to maintain cell capacitance. To address this challenge, research has explored the use of tetragonal HfO2 layers, which theoretically possess a higher dielectric constant than ZrO2, as dielectrics. However, the thermodynamically stable phase of HfO2 is monoclinic with a lower dielectric constant, necessitating a phase transition to the tetragonal form for DRAM capacitor applications. Although attempts have been made to induce this phase transition to achieve high dielectric constants by applying an HfO2/ZrO2 layered structure or doping HfO2 with elements such as Zr, Al, and Si, significant challenges remain in completely eliminating the monoclinic phase or implementing a pure tetragonal phase of HfO2. In this study, we systematically investigated the crystallinity changes and improved the electrical properties of HfO2/ZrO2 layered structures with Al doping in the HfO2 layers. Our findings demonstrate that optimizing the partitioning of the ZrO2 and HfO2 layers, combined with Al doping, effectively achieves equivalent oxide thickness scaling.

Design and optimization of two-terminal InGaP/Si tandem solar cell through numerical simulation

Abstract The III-V/Si double junction solar cells demonstrate cost-effective performance comparable to III-V/III-V tandems, with an efficiency of 35.9%, below the 43% theoretical limit. Considering monolithic InGaP//Si based tandem solar cell, this work dealt with the optimization of its efficiency as a function of layer thicknesses and dopings. Considering ideal optoelectronic parameters of materials, numerical simulations were performed by using Silvaco/ATLAS TCAD software. They were conducted within the context of a multi-step optimization procedure that was proposed in this work. The obtained optimum tandem InGaP//Si structure reached an unprecedented power conversion efficiency of 40.74% under 1.5G spectrum.

Comparison between InAs-based and GaSb-based interband cascade lasers with hybrid superlattice plasmon-enhanced claddings

We compare InAs-based and GaSb-based interband cascade lasers (ICLs) with the same 12-stage active region designed to emit at a wavelength of 4.6 µm. They employ a hybrid cladding architecture with the same geometry and inner claddings consisting of InAs/AlSb superlattices but different outer claddings: The InAs-based ICL employs plasmon enhanced n-type doped InAs layers while the GaSb-based ICL employs plasmon-enhanced n-type doped InAs0.915Sb0.085 claddings lattice matched to GaSb. Due to the lower refractive index of n + -InAsSb (n = 2.88) compared to n+ -InAs (n = 3.10) and higher refractive index of separate confinement layers, the GaSb-based ICL shows a 3.8% higher optical mode confinement in the active region compared to the InAs-based ICL. However, the InAs-based ICL has 15.3% lower free carrier absorption losses than the GaSb-based ICL, resulting in approximately equal threshold gains. Experimentally operated in pulsed mode and at room temperature, the GaSb-based ICL shows a 15.3% lower threshold current density, but also 12.8% higher threshold voltage resulting in comparable threshold power densities. Also presented is the influence of geometry and doping variation on confinement factors and calculated free carrier absorption losses in the GaSb-based ICL.

Thickness and Doping Density Influence of a High-Voltage Inorganic Perovskite Solar Cell: A SCAPS 1-D Simulation Study

Recently, all inorganic perovskite solar cells have triggered great attention thanks to the rising performance during their development in solid state photovoltaics showing enhanced characteristics, such as: good stability, high photoluminescence quantum yield, tunable size, and morphology. In this work, a high open-circuit voltage solar cell based on all-inorganic perovskite through SCAPS simulator program is presented by analysing electron transport layer (ETL), perovskite layer, hole transport layer (HTL) thickness and doping density from a FTO/TiO2/CsPbBr3/Spiro-OMeTAD/Au structure were modified to observe its influence on solar cell performance. Therefore, simulation results show that a thicker ETL hinders carrier transport towards the FTO layer due to larger distance which leads to higher recombination rate, reducing carrier’s lifetime. Albeit high doping density values in ETL enhances the overall solar cell performance. As for the absorber layer, while its thickness increases, carrier collection rate decreases due to recombination impacting Voc, which results from thickness increase. Based on the results, solar cell efficiency improvement is attributed to the built-in electric field as absorber layer doping density increases. While HTL thickness has minimum impact on the solar cell output, doping density enhances device parameters significantly. Summarising the results obtained from thickness and doping density simulations, the optimal solar cell operation was obtained at 10 nm, 600 nm, and 100 nm layer thickness as well as 1020 cm-3, 1016 cm-3, and 1020 cm-3 doping density (TiO2, CsPbBr3 and Spiro-OMeTAD). Results from three different sources, collected from literature, were used to compare, and fitting them along with simulation results.

Achieving 34 % efficiency with a dual-absorber solar cell design using CaRbCl3 and Ca3NCl3 perovskites

This study’s DFT calculations show that the direct bandgaps of perovskite CaRbCl3 and Ca3NCl3 are 1.386 eV and 1.430 eV, respectively, confirming their semiconducting nature. The study also provides density of states and dielectric constant data for these materials. In photovoltaic (PV) technology, perovskites are highly valued as solar absorber materials for their exceptional optical properties, low cost, high efficiency, and lightweight design. This study presents a structure (Al/FTO/CdS/dual absorber (CaRbCl3/Ca3NCl3)/V2O5/Au) incorporating a CdS electron transport layer (ETL) and a V2O5 hole transport layer (HTL) with a double perovskite absorber layer (DPAL) of CaRbCl3 and Ca3NCl3 using SCAPS-1D. The results show that the DPAL-based perovskite solar cell (PSC) outperforms single-layer PSCs, with significant efficiency gains when HTL is included. The study thoroughly examines the effects of layer thickness, doping levels, and defect densities on key electrical parameters such as VOC, JSC, FF, and PCE. It also explores J-V and QE characteristics and the impact of temperature. The ideal absorber thickness for achieving the highest PCE is 500 nm for CaRbCl3 and 600 nm for Ca3NCl3, combined with a doping density of 1 × 1017 cm−3, a defect density of 1 × 1011 cm−3 and interface defect density of 1 × 1010 cm−2. While single-absorber solar cells achieve maximum efficiencies of 24.40 % (CaRbCl3) and 24.02 % (Ca3NCl3), the DPAL setup reaches an optimized efficiency of 27.66 %, further increasing to 34.39 % with a VOC of 1.295 V, FF of 83.95 %, and JSC of 31.63 mA/cm2 when using V2O5 HTL. This research provides valuable insights and a practical strategy for developing cost-effective CaRbCl3/Ca3NCl3 thin-film solar cells.

Improvement of LiFePO4 electrochemical performance by organic zinc source doping in combination with crystalline carbon layer capping

In this paper, LiFePO4 cathode materials are prepared by hydrothermal method and co-modified using the synergistic effect of doping and capping. We investigate the effects of Zn[Formula: see text] doping and DPHP capping layer on the crystalline, microstructure, and electrochemical properties of LFP cathode materials, and the results indicate that the discharge capacity of the co-modified cathode material with 5% Zn[Formula: see text] doped and 7% DPHP capping layer is 162.1 mAh ⋅ g[Formula: see text], and the rate of capacity retention is still as high as 98.5% after 200 times of discharging and charging.

Synergistic enhancement of lithium iron phosphate electrochemical performance by organic zinc source doping and crystalline carbon layer capping

In this study, lithium iron phosphate (LFP) is prepared as cathode material by hydrothermal synthesis method and the combined effect of doping and capping is applied to co-modify it. We thoroughly investigate how Zn2+ doping and PA capping layer affect the crystal structure, microscopic morphology, and electrochemical properties of LFP cathode materials. The experimental results show that when co-modified with 5 % Zn2+ doping combined with 7 % PA capping layer, the resulting cathode material exhibits a discharge specific capacity of 165.5 mAh g−1, and the capacity retention rate can still be maintained at a high level of 98.6 % after 200 charge–discharge cycles.

High-Entropy Layered Oxide Cathode Materials with Moderated Interlayer Spacing and Enhanced Kinetics for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) with low cost and environmentally friendly features have recently attracted significant attention for renewable energy storage. Sodium layer oxides stand out as a type of promising cathode material for SIBs owing to their high capacity, good rate performance, and high compatibility for manufacturing. However, the poor cycling stability of layer oxide cathodes due to structure distortion greatly impacts their practical applications. Herein, a high entropy doped Cu, Fe, and Mn-based layered oxide (HE-CFMO), Na0.95Li0.05Mg0.05Cu0.20Fe0.22Mn0.35Ti0.13O2 for high-performance SIBs, is designed. The HE-CFMO cathode possesses high-entropy transition metal (TM) layers with a homogeneous stress distribution, providing a moderated interlayer spacing to maintain the structure stability and enhance Na+ ion diffusion. In addition, Li doping in TM layers increases the Mn valence state, which effectively suppresses John-Teller effect, thus stabilizing the layered structure during cycling. Furthermore, the use of nontoxic and low-cost raw materials benefits future commercialization and reduces the risk of environmental pollution. As a result, the HE-CFMO cathode exhibits a super cycling performance with a 95% capacity retention after 300 cycles. This work provides a promising strategy to improve the structure stability and reaction kinetics of cathode materials for SIBs.

Charge Transfer Plasmonics in Bespoke Graphene/α-RuCl3 Cavities.

Surface plasmon polaritons (SPPs) provide a window into the nano-optical, electrodynamic response of their host material and its dielectric environment. Graphene/α-RuCl3 serves as an ideal model system for imaging SPPs since the large work function difference between these two layers facilitates charge transfer that hole dopes graphene with n ∼ 1013 cm-2 free carriers. In this work, we study the emergent THz response of graphene/α-RuCl3 heterostructures using our home-built cryogenic scanning near-field optical microscope. Using phase-resolved imaging, we clearly observe long wavelength, heavily damped THz SPPs in a series of variable-size graphene cavities. From this, we extract the plasmonic wavelength and scattering rate in the graphene/α-RuCl3 heterostructures. We determine that the measured plasmon wavelength and electronic scattering rate match our heterostructures' theoretically predicted values. Our results demonstrate that shaping graphene into bespoke cavity structures enables observation and quantification of SPPs in heavily doped graphene that are largely not addressable with other experimental techniques. Moreover, the manifest lack of metallicity observed in the adjacent doped α-RuCl3 layer provides significant constraints on the nature of the interfacial charge transfer in this 2D heterostructure.

Numerical optimization of inorganic p-Sb2Se3/n-ZrS2 heterojunction solar cells: achieving high efficiency through SCAPS-1D simulation

p-Sb2Se3 and n-ZrS2 materials show strong potential for cost-effective photovoltaic applications. This study presents a detailed numerical analysis of p-Sb2Se3/n-ZrS2 heterojunction solar cells using SCAPS-1D, focusing on how key parameters such as layer thickness, doping density, and bandgap have affected device performance. Critical photovoltaic metrics, such as built-in voltage (Vbi), carrier lifetime, depletion width (Wd), recombination rates, and photogenerated current, were examined. Our findings demonstrate that optimizing the p-Sb2Se3 absorber layer with a 1.0 eV bandgap, 5000 nm thickness, and doping density of 1020 cm−3 leads to a maximum efficiency of 32.14%, with a fill factor (FF) of 84.57%, short-circuit current density (Jsc) of 47.61 mA cm−2, and open-circuit voltage (Voc) of 0.792 V. For the ZrS2 buffer layer, the best performance was achieved with a 1.2 eV bandgap, 200 nm thickness, and doping density below 1 × 1020 cm−3. These optimized parameters significantly enhanced carrier separation and minimized recombination losses, leading to improved power conversion efficiency. In addition to theoretical optimization, this study emphasizes the practical potential of these materials for real-world applications. The combination of Sb2Se3 and ZrS2 offers a low-cost fabrication process suitable for scalable commercial solar cell production while maintaining high efficiency. These results underscore the viability of p-Sb2Se3/n-ZrS2 heterojunctions as promising candidates for next-generation clean energy solutions.

Lead-free Cs2TiBr6 perovskite solar cells achieving high power conversion efficiency through device simulation

Recently, lead-based perovskite solar cells (PSCs) have gained significant attention in the photovoltaic industry due to their remarkable properties such as high bandgap and high absorption coefficient. However, challenges such as toxicity, instability, and short shelf life limit the use of inorganic-organic lead-based PSCs. To address these issues, researchers introduced eco-friendly, lead-free, and stable cesium titanium (Cs2TiBr6) single-halide absorber material. The aim of this work is to perform the numerical modelling and simulation of FTO/SnO2/Cs2TiBr6/CBTS/Au structure incorporating interfacial defect layers (IDL) using SCAPS-1D to examine and study its characteristics properties about various photovoltaic (PV) parameters such as light-absorbing layer thickness, charge transport layer thickness, doping, defect density, operating temperature, and quantum efficiency (QE). After evaluating these parameters, the proposed single-halide Cs2TiBr6-based structure shows superior performance as compared to previously reported experimental and simulation-based Cs2TiBr6 perovskite structures. The results show a maximum power conversion efficiency (PCE) of 24.24 %, with a fill factor (FF) of 88.9 %, an open-circuit voltage (VOC) of 1.31 V, and a short-circuit current density (JSC) of 20.76 mA/cm2. This work encourages researchers to develop low-toxic, and stable PSCs for the future solar cell industry.

Transition Metal Dichalcogenides in Electrocatalytic Water Splitting

Two-dimensional transition metal dichalcogenides (TMDs), also known as MX2, have attracted considerable attention due to their structure analogous to graphene and unique properties. With superior electronic characteristics, tunable bandgaps, and an ultra-thin two-dimensional structure, they are positioned as significant contenders in advancing electrocatalytic technologies. This article provides a comprehensive review of the research progress of two-dimensional TMDs in the field of electrocatalytic water splitting. Based on their fundamental properties and the principles of electrocatalysis, strategies to enhance their electrocatalytic performance through layer control, doping, and interface engineering are discussed in detail. Specifically, this review delves into the basic structure, properties, reaction mechanisms, and measures to improve the catalytic performance of TMDs in electrocatalytic water splitting, including the creation of more active sites, doping, phase engineering, and the construction of heterojunctions. Research in these areas can provide a deeper understanding and guidance for the application of TMDs in the field of electrocatalytic water splitting, thereby promoting the development of related technologies and contributing to the solution of energy and environmental problems. TMDs hold great potential in electrocatalytic water splitting, and future research needs to further explore their catalytic mechanisms, develop new TMD materials, and optimize the performance of catalysts to achieve more efficient and sustainable energy conversion. Additionally, it is crucial to investigate the stability and durability of TMD catalysts during long-term reactions and to develop strategies to improve their longevity. Interdisciplinary cooperation will also bring new opportunities for TMD research, integrating the advantages of different fields to achieve the transition from basic research to practical application.

Optimization and characterization of doped photoactive layer P3HT: ICBA for organic optoelectronic applications

A doped bulk heterojunction P3HT: ICBA active layer was studied, aiming at the effects of chromium chloride (CrCl2) and Cobalt chloride (CoCl2) doping. The study involved linear optical and electrical characterization to analyze the impact of these additives on the photoactive layer's performance. The electrical properties of doped P3HT: ICBA revealed enhancements with CrCl2(5%wt), CrCl2(10%wt), CoCl2(5%wt), and CoCl2(5%wt) (5%wt) by 8.5x, 11x, 10x, and 14x respectively, compared to pure P3HT:ICBA under dark/light conditions. This improvement is attributed to enhanced internal charge generation. The study also examined the effect of thermal treatment on the active layer from 20 ºC to 65 ºC under dark/light conditions. Additionally, the doped photoactive layer samples were tested as optical sensors under white, green, and red light, with a slightly higher optical response under white light. The findings confirm that doping P3HT: ICBA with CoCl2 and CrCl2 improves optical and electrical responses due to better charge transfer and generation.

Complex Diagnostics of Silicon-on-Insulator Layers after Ion Implantation and Annealing

A technology was developed for activating ion-implanted dopants in silicon-on-insulator layers at a low annealing temperature (600°C) using the pre-amorphization technique of a silicon device layer. In the case of phosphorus implantation, silicon was amorphized directly by dopant ions. In the case of boron implantation for pre-amorphization, the layers were preliminary irradiated with argon or fluorine ions. Complex diagnostics of the implanted layers was carried out using secondary ion mass spectrometry, X-ray diffractometry and small-angle X-ray reflectometry. The combination of methods made it possible to characterize the impurity distribution, the degree of silicon crystallinity, the layer thicknesses, and the interface widths in structures. The results of diagnostics of the structure and composition correlate well with calculations in the SRIM software package and the electrophysical characteristics of the layers after annealing. It was shown that the use of argon for pre-amorphization of silicon interfered with the recrystallization process and did not make it possible to achieve acceptable electrical characteristics of the doped layer. Amorphization with phosphorus and pre-amorphization with fluorine during boron implantation allowed obtaining the required values of the resistance of the doped layers after annealing at a temperature of 600°C. The use of a complex approach made it possible to optimize the modes of amorphization, ion doping, and annealing of silicon-on-insulator structures at low temperatures, necessary for the creation of light-emitting device structures based on silicon-germanium nanoislands.

Theoretical design and performance evaluation of a lead-free fully inorganic CIGS solar cell with CuSbS2 as HTL

The widespread use of lead (Pb)-based materials in solar cells poses serious environmental and health risks, particularly through lead contamination. These hazards make the development of Pb-free alternatives a critical priority for safer and more sustainable photovoltaic technologies. This study addresses this pressing need by exploring innovative, non-toxic materials for high-efficiency solar cells. In response, this study introduces a novel, fully inorganic solar cell structure, FTO/ZnO/CIGS/CuSbS2/Au, which leverages copper indium gallium (di) selenide (CIGS) as the absorber layer and copper antimony sulfide (CuSbS2) as the hole transport layer (HTL). Our approach is distinguished by the strategic integration of zinc oxide (ZnO) as the electron transport layer (ETL), which, in conjunction with CuSbS2, enhances charge transport efficiency and overall device performance. This research innovates by conducting a comprehensive numerical analysis to fine-tune critical parameters such as absorber layer thickness, doping levels, defect densities, and radiative recombination rates. By optimizing these parameters, we significantly improve the photoconversion efficiency of the solar cell. Additionally, we systematically investigate the influence of interface defects, metal back contacts, and temperature variations on device performance, providing new insights into the stability and efficiency of inorganic solar cells. A key mechanism explored in this study is the role of series and shunt resistances in determining the electrical behavior of the solar cell, analyzed through capacitance-voltage (C–V) and capacitance-frequency (C–F) measurements. These analyses reveal the intricate balance between charge carrier dynamics and external resistive factors, further elucidating the operational mechanisms within the cell. Our fully inorganic FTO/ZnO/CIGS/CuSbS2/Au solar cell achieves a remarkable power conversion efficiency (PCE) of 32.25 % at room temperature, with a short-circuit current density (JSC) of 34.77 mA/cm2, an open-circuit voltage (VOC) of 1.10 V, and a fill factor (FF) of 84.33 %. By comparing these results with both experimental and theoretical benchmarks in the field of CIGS solar cells, we demonstrate the competitive edge and profound significance of our lead-free design.

Assessment of photovoltaic efficacy in antimony-based cesium halide perovskite utilizing transition metal chalcogenide

Antimony-based perovskites have been recognized for their distinctive optoelectronic attributes, standard fabrication methodologies, reduced toxicity, and enhanced stability. The objective of this study is to systematically investigate and enhance the performance of all-inorganic solar cell architectures by integrating Cs3Sb2I9, a perovskite-analogous material, with WS2—a promising transition metal dichalcogenide—used as the electron transport layer (ETL), and Cu2O serving as the hole transport layer (HTL). This comprehensive assessment extends beyond the mere characterization of material attributes such as layer thickness, doping levels, and defect densities, to include a thorough investigation of interfacial defect effects within the structure. Optimal efficiency was observed when the Cs3Sb2I9 absorber layer thickness was maintained within the 600-700 nm range. The defect tolerance for the absorber layer was identified at 1×1015/cm3, with the ETL and HTL layers exhibiting significant defect tolerance at 1×1016/cm3 and 1×1017/cm3, respectively. Furthermore, this study calculated the minority carrier lifetime and diffusion length, establishing a strong correlation with defect density; a minority carrier lifetime of approximately 1 µs was noted for a defect density of1×1014/cm3 in the absorber layer. A noteworthy finding pertains to the balance between the high work function of the back contact and the incorporation of p-type back surface field layers, revealing that interposing a highly doped p+ layer between the Cu2O and the metal back contact can elevate the efficiency to 21.60%. This approach also provides the freedom to select metals with lower work functions, offering a cost-effective advantage for commercial-scale applications.

Enhanced CZTSSe Thin‐Film Solar Cell Efficiency: Key Parameter Analysis

This work presents a numerical simulation study on CZTSSe‐based thin‐film solar cells using Silvaco Atlas software, focusing on optimization and loss analysis. Starting from an initial power conversion efficiency of 12.73%, the ZnO/CdS/CZTSSe cell structure is systematically optimized. Through precise adjustment of layer thickness and doping density, the efficiency is improved to 18.75%. The optimal parameters are 2.5 μm (1017 cm−3) for CZTSSe, 0.01 μm (1018 cm−3) for CdS, and 0.02 μm (1019 cm−3) for ZnO. Loss analysis reveals that increasing CZTSSe thickness beyond 2.5 μm leads to higher bulk series resistance, while thicker CdS and ZnO layers reduce photocurrent generation. Doping density significantly impacts open‐circuit voltage, while layer thickness primarily affects short‐circuit current and fill factor. Performance improves at lower temperatures, achieving 22.2% efficiency at 250 K. These findings provide valuable insights for developing high‐efficiency CZTSSe solar cells.