Lead free perovskites have drawn considerable attention in last few years. Tin (Sn) have potential to replace lead (Pb), however Sn4+ caused by oxidation of Sn deteriorates the solar cell performance. In this article, we have presented the design and fabrication of FASnI3 solar cell and analyze the impact of various parameters on the efficiency of cell module. In addition, we have used solvent engineering with SnF2 as a blockage of Sn4+. We have achieved 6.01% efficiency with fabricated device using FASnI3 as an active layer. Furthermore, the roles of the defect, interface, contact work function, and charge selecting layer on the efficiency of device have been rigorously investigated. With optimized process parameters, the device efficiency can be further improved up to 18.76%

Cesium tin iodide (CsSnI3) has been suggested as a practical environmentally friendly rival to perovskite solar cells (PSCs) due to its negligible environmental effect and good optoelectronic features. The widespread use of CsSnI3 PSCs is hindered by the quick (often just a few minutes) transition from Sn2+ to Sn4+. By incorporating SnF2 into the perovskite layer, we provide techniques for creating stable CsSnI3 PSCs. The built-in device has a maximum power conversion efficiency (PCE) of 5.52%. The SnF2 incorporated devices sustain 52.18% of their initial absorption after 120 min. Furthermore, a device model was created in order to investigate influence of various perovskite parameters. With optimal absorber thickness of 300 nm, defect density nearly around 1013 cm−3, capture cross section area of electron and hole below 10−16 cm2 and doping concentration around 1019 cm3 breakthrough efficiency up to 16.35% can be achieved. Based on the findings, a desirable understanding of the operation of CsSnI3 devices is provided.

With lead-based perovskite materials, lead content and long-term stability are the big concerns. Recently, Cesium tin iodide (Cs2SnI6) double perovskite has gained recognition as a stable and environment-friendly photovoltaic material compared to lead-based perovskite materials. In the present study, we have investigated Cs2SnI6 based solar cell with all inorganic transport materials using SCAPS-1D. The optimized device exhibited a maximum efficiency of about 18%. Further we fabricated Cs2SnI6 perovskite films using a solution process approach, utilizing CsI and SnI4 in a 2:1 ratio. For synthesized double perovskite film, the crystallinity, morphologies, and optical characteristics were examined. Additionally, the stability analysis confirmed that the prepared perovskite films were stable for more than two months under ambient exposure. Finally, utilizing the synthesized Cs2SnI6 thin films as an absorber material, we fabricated two solar cells without and with hole transport layer (HTL), having configurations of glass/FTO/ZnO/Cs2SnI6/Ni and glass/FTO/ZnO/Cs2SnI6/ MoS2/Ni, respectively, in the ambient conditions. As a major finding, it has been observed that the inclusion of MoS2 as HTL improved overall performance, with an enhancement in the power conversion efficiency (PCE) of nearly 45% compared to the device without HTL.

As lead halide perovskites face toxicity and stability issues, research on the eco-friendly double perovskite Cs2AgBiBr6 has become increasingly popular. While the majority of research on this Cs2AgBiBr6 perovskite material has been concentrated on photovoltaic performance and promising applications, its enduring stability and degradation process have received far less attention. This article presents a thorough numerical analysis of an eco-friendly Cs2AgBiBr6 double perovskite solar cell (PSC) model with a standard n-i-p architecture FTO/C60/Cs2AgBiBr6/MoS2/Pt. In-depth research has been done on several device characteristics, including the defect density and the thickness of the electron transport layer (ETL), hole transport layer (HTL), and absorber layer, and back-contact electrode work function. Through parameter optimization, we were able to achieve an open-circuit voltage (V oc) of 0.84 V, short-circuit current density (J sc) of 32.28 mA/cm2, and fill factor (FF) of 85.77% with power conversion efficiency (PCE) of 23.49% under AM1.5G illumination, which is significantly greater than the highest stated values identified in the literature.

Pressure Sensors plays pivotal role in the domain of soft robotics to interact with the real environment. In this study, we have reported the design and optimization of the hyper-elastic multi-axial strain and contact pressure sensor. The proposed sensor capable of detecting multi-axis strains and contact pressure consists of multilayered micro-channels filled with a liquid metal. The molds of the multilayered channel patterns were created with 3D printer and laser cutting machine to fabricate the sensor device. Silicone rubbers have been poured in the molds and solidify to make structure of sensor. These structures bonded for making of embedded micro-channels, and a liquid metal was infused into the micro-channels. The optimized channel dimensions were 0.33mm width, 0.35mm height, and no. of turns were 14 for strain sensing. The optimized parameters were 0.39 mm width and 0.35 mm height for pressure sensing.

Gold nanoparticles (AuNPs) were incorporated beneath the electron-beam evaporated ZnO thin films. The thin films were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, Raman spectroscopy and photoluminescence spectroscopy (PL). The combined results of PL and Raman indicated the existence of many point defects in the bare ZnO film itself including the presence of oxygen vacancy. The red shift in one of the prominent Raman modes at 562 cm−1 (from the usually observed position of 574 cm−1) indicated the existence of tensile stress in the films. Due to the presence of AuNPs, whereas PL emissions showed Burstein-Moss effect, Raman spectra showed SERS effect. The carrier concentration was found to increase from ~ 9 × 1021 m−3 for bare ZnO/glass to ~ 26 × 1022 m−3 for ZnO/AuNPs/glass. The study of electrical properties indicates that photoconductivity of ZnO thin films can be easily controlled by simply incorporating the tunable AuNPs underneath. Unlike many recent studies on AuNPs–ZnO heterostructures, the present study proposes simple method to incorporate AuNPs to control the properties of ZnO in thin film form. This study will add to the research on optoelectronics.

This article presents the impact of different radio frequency (RF) power during deposition on the ZnO thin films properties, deposited using RF sputtering deposition technique. The effect of these process parameters on the structural, morphological, electrical and optical properties are elaborated in detail. The crystalline quality and optical parameters of the films are affected by RF power variation during film deposition. The film’s crystal quality was reasonably decent with the RF power reaching 100 W. For a 5 µm × 5 µm scan area, the RMS roughness value changed from 1.29 to 3.22 nm as the PRF increases from 50 to 100 W. FESEM images depicts the decrement in grain size of ZnO thin film as RF power increases. When the RF power was varied during deposition, both mobility and carrier concentrations changed. Blue shift was observed in UV emission with increasing RF power.

In this study, we discuss a simulation model for a tandem device with MAPbSnI3 as a bottom subcell having bandgap of 1.2 eV and MACsPb(I0.6Br0.4) as a top subcell having bandgap of 1.8 eV. These perovskite material-based top and bottom cells are first examined under standalone condition. Simulation result shows the efficiency of standalone MAPbSnI3 and MACsPb(I0.6Br0.4) devices to be 15.34% and 12.74% respectively. These results are consistent with previously reported experimental findings. We have also analyzed the effect of defect density, perovskite thickness and contact work function on overall efficiency of the solar cell. It has been found that defect density in the perovskite layer should be smaller than 1013 cm−3 and the optimal work function for the front contact of the perovskite solar cell was found to be 5.44 eV, while for the back contact it is 4.22 eV for optimal performance of the solar cell. The matching of tandem stacks is investigated in terms of the equal short-circuit currents of subcells. This condition is met at perovskite thicknesses of 400 nm and 150 nm for MAPbSnI3 and MACsPb(I0.6Br0.4), respectively. Finally, to evaluate tandem solar cell performance, the top cell was operated under the standard AM 1.5 spectrum retaining perovskite thickness at 400 nm, while the bottom cell efficiency was calculated in a filtered spectrum. Improved efficiency of 20% is obtained for the MACsPb(I0.6Br0.4)/MAPbSnI3 tandem solar cell. The analysis and findings reported in this work give a potential route for tandem solar cell design.

The memristor is a novel nanostructured resistive tuning two-terminal electronic device that has been widely explored in the areas of neuromorphic computing systems, memory, digital circuits, analog circuits, and many more new applications. In this article, an efficient and flexible window function is presented for a linear drift memristor model. The proposed parametric cubic parabolic window function provides a unique feature (controllable window function discontinuity at the boundaries) to a linear drift memristor model by which the distorted pinched hysteresis loop problem is resolved and the number of programming resistance states of the memristor is improved. Five control parameters are introduced in the proposed window function in order to correct the existing problems (such as boundary effect, boundary lock and inflexibility) and are able to provide asymmetric nonlinearity at the boundaries of the device, making it feasible for tracking the resistive switching dynamic of a futuristic oxide-based memristive device with different inert electrodes. The proposed model is validated with a solution-processed ZnO-based fabricated memristive device. A programmable analog gain amplifier circuit is ultimately executed to simulate the utilization of the evolved memristor model, and the effect of memristance resolution is investigated.

In this article, we have studied an identical section of a core-shell ZnO Nanorod (NR) based lead-free perovskite solar cell. Various factors affecting the solar cell's performance have been rigorously investigated for device optimization; specifically, the length and diameter of the ZnO NR core, perovskite shell thickness, thickness of perovskite cap layer, and hole transport layer (HTL) thickness. The defect density of states (DOS) in the perovskite absorber layer and the effect of interface defect density on the performance of the cell are also studied. We obtained power conversion efficiency (PCE) of 14.50%, the open-circuit voltage (VOC) of 0.96 V; short-circuit current density (JSC) of 18.11 mA/cm2 and Fill factor (FF) of 83.35%. We also analyzed the effect of tilt or inclination of NR on the performance of the cell which is a crucial factor toward achieving high performance. By optimizing the device parameters, we have achieved a PCE of 21.27%, VOC of 0.97 V, JSC of 29.56 mA/cm2, and FF of 84.15% at an inclination of 10-degree tilt with respect to the incident light under AM 1.5 illumination. The shadowing mechanism behind efficiency droop is also presented to further realize an optimal design high-performance PSC.

— This work reports the growth optimization and analysis of ZnO, MgxZn1-xO, and CdxZn1-xO thin films on silicon substrate using an electron beam evaporation system. The crystal phase purity, surface morphology, optical and electrical properties of deposited ZnO, MgxZn1-xO, and CdxZn1-xO thin films were studied. X-ray diffraction (XRD) spectra revealed that the deposited films were polycrystalline in nature with preferred (002) crystal orientation. Field emission scanning electron microscope study showed a dense-packed grained structure with an exact symmetrical distribution. The root-mean-square roughness of 3.03 nm was perceived by atomic force microscopy measurement for MgxZn1-xO thin-film, indicating good morphology of the deposited film. Photoluminescence measurement demonstrated a near-band-edge emission peak around 363 nm for ZnO thin film. The energy band gap obtained for ZnO, MgxZn1-xO, and CdxZn1-xO were 3.36 eV, 3.86 eV, and 2.89 eV, respectively, as measured by Ultraviolet–Visible spectroscopy. The higher amount of photocurrent was detected in illumination condition compared to dark condition with responsivity 0.54 AW-1 for ZnO films, making it suitable for photodiodes applications.

Tin-based perovskite solar cell (PSC) has witnessed a focus in recent years. In this article, an inverted p-i-n planar hetero-junction structure for FASnI3 PSC is realized using device simulation software. We have studied the effect of relative permittivity ( varepsilon _{text {r}} ), carrier lifetime ( tau ), and thickness on the performance of PSC. The fill factor (FF) is strongly dependent on carrier lifetime. In a uniformly doped device, maximum efficiency is obtained for high tau (>50 ns). Furthermore, the transport of charge carrier to the electrode is connected to the electric field. For low varepsilon _{text {r}} , the electric field strength is high thus recombination of light generated carriers is low. The impact of different recombination effects on cell performance is also discussed. It is found that Shockley-Read-Hall (SRH) recombination is a major reason for the performance degradation of perovskite cells. The result shows that with optimized absorber properties, power conversion efficiency (PCE) 17.33% can be achieved. This study will aid researchers for better understanding of carrier dynamics process thus achieving high device efficiency in lead-free PSCs.

ZnO- and MgZnO-based single- and double-layer heterostructures have been grown using an electron-beam evaporation system. Structural, morphological, optical and electrical characteristics were elaborated for all the configurations. Using x-ray diffraction, it was inferred that a hexagonal wurtzite structure is maintained for both ZnO and MgZnO with fairly good crystallinity. Field emission scanning electron microscopy (FESEM) images showed the homogeneous distribution of particles in ZnO and MgZnO throughout the films. Both atomic force microscopy and FESEM images exhibit a larger size for ZnO particles. The UV emission for ZnO at ∼371 nm and MgZnO at ∼359 nm was anticipated from photoluminescence spectra. The visible photoconductive properties of all the different configurations were studied in the dark and under the illumination of a white light source. The highest responsivities measured for the ZnO/MgZnO/Si structure were 0.242 A W-1 and 0.164 A W-1 for as deposited and annealed at 400 °C, respectively. These results show the suitability of bilayer photo detectors for visible light detection.

With the advancement of technology, highly efficient eco-friendly perovskite solar cells (PSCs) are desirable candidates for energy applications. In this article, we propose a design approach and potentiality of promising Pb-free PSC to analyze the different parameters. Different design strategies and factors such as defect density, characteristic decay energies, and capture cross section area have investigated using device simulation software. The defects in absorber layer are modeled by using exponentially decaying band tails for shallow-level defects and Gaussian distribution for the deep-level defects. By optimizing the device parameters, we have achieved a simulated conversion efficiency of 13.35% with open-circuit voltage ( Voc ) = 0.89 V, short circuit current density ( Jsc ) = 22.79 mA/cm2, and a fill factor (FF) = 65.28% under AM1.5G illumination. We have also studied the impact of absorber layer thickness and interface defect density on the performance of the solar cell. These simulation results can aid researchers in a reasonable choice of materials and optimally design high-performance PSC.

ZnO thin films are most promising materials for various emerging applications. In this report, we have compared the physical properties of ZnO thin films deposited at room temperature by three frequently used physical vapor deposition methods, namely, electron beam evaporation, pulsed laser deposition (PLD), and radio frequency (RF) sputtering. The structural, morphological, optical and electrical properties of the deposited ZnO thin films were compared systematically using X-ray diffraction, scanning electron microscopy, atomic force microscopy and UV–visible spectrophotometry. All the films showed polycrystalline nature, with the film deposited using PLD being found to be of highest crystalline quality. Uniformly distributed and densely packed particles were realized throughout the film for all the techniques. The films show notable transparent nature in the visible range of the electromagnetic spectrum. Distinctly visible UV emission was observed for the PLD and RF technique, indicating the suitability for making light-emitting diode and photodiode. E-beam-deposited films showed high porosity which is ideal for designing gas sensors.

Lead toxicity and stability are major hurdles in commercialization of the perovskite solar cell. We present the theoretical investigation and analysis of eco-friendly and stable CsSnGeI3 based solar cell. For better understanding of material parameter, various factors affecting the cell performance such as thickness, doping concentration, defect density and doping density of charge transport layer have been rigorously investigated. From simulation results, we observed that the device performance extensively depends on defect density and doping concentration of perovskite absorber layer. We have proposed Cesium Tin–Germanium Tri-iodide (CsSnGeI3) as an efficient light absorber material as compared to lead counterparts. With optimized parameters of proposed architecture, we have achieved 13.29% efficiency. We have also done the comparative analysis of different hole transport layer (HTL) layers to replace spiro-OMeTAD. The results indicate that CsSnGeI3 can be a great prospective to be an absorber layer for high-efficiency perovskite solar cells.

A comprehensive numerical modelling and analysis have been carried out for perovskite solar cell using device simulation software. Rigorous theoretical investigation have been performed for optimization of device parameters more specifically absorber layer. We have obtained the optimum cell performance having PCE (η) = 21.5%, FF = 87.4, Jsc=23.4mA/cm2, Voc=1.05V. We have also studied effect of recombination and trap densities on the performance of cell module. This work will provide guidelines for reasonably selecting material for highly efficient perovskite solar cell.

In this paper a design approach for Zinc Oxide (ZnO) based p-i-n structure photodiode is demonstrated for ultraviolet (UV) detection. The peak sensitivity occurs at a range of 320nm to 340nm. The detection range can be further decreased by suitably alloying ZnO with MgO. Rigorous theoretical investigation has been performed for the device optimization to improve the responsivity. The optimization involves doping concentration and thickness calibrations of various constituent layers of the device. These results indicates that ZnO based photodetectors are good candidates for detecting ultraviolet radiation.