The fabrication of sputtered indium tin oxide (ITO) nanorod arrays offers a promising and economical approach to improving light management in photovoltaic devices. In this study, we introduce a novel light-trapping approach using a sputtered ITO nanorod array as a substitute for traditional surface texturing. We successfully fabricated a hydrogenated amorphous silicon (a-Si:H) p-i-n solar cell on the ITO nanorod substrate and compared its performance to a standard reference device. The ITO nanorods, grown at 320 °C, exhibited excellent optical properties, with a diffused-to-total transmitted light ratio exceeding 50

In the quest for environmentally friendly and highly efficient perovskite solar cells (PSCs). The present study has designed and numerically optimized a novel, cost effective dual absorber FTO/TiO2/CsSnI3/Cs3Sb2Br9/Spiro-OMeTAD/Ni. This novel configuration leverages the synergistic properties of narrow bandgap absorber (NBA) CsSnI3 and wide bandgap absorber (WBA) Cs3Sb2Br9 to broaden the absorption spectrum and enhance device performance. Initial simulations using SCAPS-1D yielded a power conversion efficiency (PCE) of 24.80 %, with an open-circuit voltage (Voc) of 1.160 V, a short-circuit current density (Jsc) of 26.54 mA/cm2, and a fill factor (FF) of 80.50 %. Through systematic optimization of critical device parameters-including absorber layer full thickness, thickness ratio of WBA/NBA, doping densities of absorber and ETL HTL, defect densities, and interface properties-For this attained a peak efficiency of 30.58 %, accompanied by a Voc of 1.1906 V, a Jscof 29.8387 mA/cm2, and an FF of 86.08 %. According to the latest NREL data, the highest reported efficiency for perovskite solar cells is 26.1 %. Additionally, the impact of back metal contact work function and temperature variations were analyzed and found Nickel (Ni) can be a good alternative to Gold (Au) which gives a good cost-effective solution. Our investigations reveal that a double absorber layer structure, because of broadening the absorption spectrum and enhancing cell stability, outperforms a single-absorber based PSC. These results highlight the potential of our proposed novel combination of bilayer structure to drive the development of lead-free, highperformance PSCs, offering a promising pathway for future experimental validation and large-scale application in sustainable solar energy solutions.

This study focuses on the theoretical aspects of third-generation perovskite solar cells (PSC), with the aim of replacing traditional silicon-based counterparts. With potential for higher efficiency and low manufacturing costs, perovskite cells offer unique crystallographic structures allowing adjustments to photoluminescence wavelength. This research addresses challenges in cost-effective solar spectrum utilization and optimization of parameters, device architecture, and materials for high-efficiency cells. In this study, we simulated a perovskite-based solar cell (CH3NH3SnI3) using solar cell capacitance simulator-one dimension simulator under AM 1.5G illumination. The chosen electron transport layer is TiO2, and hole transport layer is CH3NH3SnBr3. The simulation explores variations in layer thickness, defect concentration, interface defects, doping concentration and electron affinity. Additionally, we analyzed the impact of back metal contact work function and temperature variations. Results indicate optimal absorber layer thickness at 0.5 mu m. Reduced defect concentrations, increased doping concentration and a higher work function for the back contact, enhance efficiency of PSC. The initial parameters yielded a 19.79% efficiency based on base values before optimization, which increased to 26.66% after optimization. According to the latest NREL data, the highest reported efficiency for PSC is 26.1%. This research provides insights into perovskite-based solar cell design for enhanced efficiency.

Three-dimensional (3D) nano-structured electrode by transparent conducting oxide (TCO) is a considerable approach for increasing efficiency of optoelectronic devices. Indium tin oxide (ITO) is a potential candidate for anode applications due to its high conductivity and a high work function. Nanorods of indium tin oxide (ITONR) were grown on catalyst-free substrates at relatively low temperature by magnetron sputtering, which is free of any carrier gases and catalyst. An X-ray photoelectron spectroscope and a transmittance electron microscope with an energy-dispersive X-ray spectrometer were used to investigate the elemental binding states and compositions of the as-synthesized nanorods. The reported ITONR shows photo-luminance property, making it effective for photovoltaic applications. The morphology and sheet resistance of nanorod had a significant effect on the solar cell performance. Sheet resistance of 10 ohm/square and transparency of 83.6% of ITONR on SCHOTT glass was achieved. The higher surface to volume ratio, superior optical and electrical properties over flat ITO layer, makes the nanorods a potential candidate for photovoltaic application.

Amine-functionalized reduced graphene oxide (af-rGO) has been synthesized wet-chemically by modified Hummer's method. Raman spectroscopy has been carried out to confirm the presence of the amine group in rGO network. Photoluminescence (PL) spectroscopy has been conducted to reveal the PL conversion property of the af-rGO. Af-rGO colloids with different densities have been coated on a baseline amorphous silicon (a-Si:H) solar cell and the respective optical and solar performances have been compared with the baseline solar cell to optimize the suitable density, which is further validated by investigating the respective field emission scanning electron microscope (FESEM) micrograph of the surface area coverage by rGO on the top of the indium tin oxide (ITO) of the a-Si:H solar cell. The application of af-rGO on the baseline solar cell of the area of 1 cm2 demonstrated an enhancement in efficiency and short-circuit current density (JSC) of ∼1% and ∼2 mA/cm2, respectively. External quantum efficiency (EQE) measurement reveals that the reductions in sheet resistance and PL converted photons have contributed additional current toward enhanced efficiency for the af-rGO-coated a-Si:H solar cell along with reflectance benefits.

Here, we have reported the synthesis of three-dimensional, mesoporous, nano-SnO2 cores encapsulated in nonstoichiometric SnO2 shells grown by chemical as well as physical synthesis procedures such as plasma-enhanced chemical vapor deposition, followed by functionalization with reduced graphene oxide (rGO) on the surface. The main motif to fabricate such morphology, i.e., core-shell assembly of burflower-like SnO2 nanobid is to distinguish gases quantitatively at reduced operating temperatures. Electrochemical results reveal that rGO anchored on SnO2 surface offers excellent gas detection performances at room temperature. It exhibits outstanding H2 selectivity through a wide range, from ∼10 ppm to 1 vol %, with very little cross-sensitivity against other similar types of reducing gases. Good recovery as well as prompt responses also added flair in its quality due to the highly mesoporous architecture. Without using any expensive dopant/catalyst/filler or any special class of surfactants, these unique SnO2 mesoporous nanostructures have exhibited exceptional gas sensing performances at room temperature and are thus helpful to fabricate sensing devices in most cost-effective and eco-friendly manner.

This work illustrates a technology for advanced light management by introducing a nonconventional back reflector layer (BRL) in amorphous silicon (a-Si:H) solar cells. To meet this, silver sulfide (Ag2S) nanoparticles with similar to 50 nm diameter have been chosen as the nanomirror owing to its low parasitic absorption loss over a broad wavelength (300 to 1100 nm) region. The Ag2S NPs were sandwiched between two indium tin oxide (ITO) layers and placed as the back reflector layer of an a-Si:H solar cell to achieve better light trapping within the active layers. The embedded structure exhibited high reflectance (up to 93%) in the red and near-infrared region, the main working zone of a-Si:H cells. With the incorporation of such a state-of-the-art back reflector structure in a-Si:H solar cells, a photoconversion efficiency of 10.58% has been achieved, which is one of the best in this class.

Multilayered graphene deposited on a flat resistive surface has twofold benefits. Less electronic scattering reduces the sheet resistance of the combined bilayer and high photon scattering through the unavoidable wrinkles on the chemically synthesized graphene layer leads to decreased effective reflection. In this paper, wet-chemically-synthesized reduced graphene oxide (RGO) has been employed on the top of the indium-doped tin-oxide (ITO) layer. The ITO layer of optimized thickness has been deposited as an alternative antireflection coating (ARC) on a p/n junction based crystalline silicon solar cell with standard textured surface. Variation in spectral response has been studied experimentally for different thickness and surface coverage of RGO on ITO. The combined effect of reduced sheet resistance due to high surface conductivity and increased photon injection efficiency due to scattering from the wrinkles of RGO results in significant improvement in the performance of the solar cell. By employing optimum thickness of RGO, percentage enhancements of about 18% and 10%, respectively, in efficiency and short-circuit current density have been achieved over the baseline cell structure. RGO also exhibits an additional benefit as a moisture repelling layer.

In p-i-n structure a-Si solar cell a buffer layer with proper characteristics plays important role in improving the p/i interface of the cell, reducing mismatch of band gaps and number of recombination centres. However for p-i-n structure microcrystalline ( µc-Si: H) cell which has much less light induced degradation than a-Si:H cell, not much work has been done on development of proper buffer layer and its application to µc-Si:H cell. In this paper we have reported the development of two intrinsic oxide based microcrystalline layer having different characteristics for use as buffer layers at the p/i interface of µc-Si:H cell. Previously SiOx:H buffer layer has been used at the p/i interface which showed positive effects. To explore the possibility of improving the performance of p-i-n structure µc-Si:H cell further we have thought it interesting to use two buffer layers with different characteristics at the p/i interface. The two buffer layers have been characterized in detail and applied at the p/i interface of the µc-Si:H cell with positive effects on all the PV parameters mainly improves the open circuit voltage (Voc) and enhances short circuit current (Isc). The maximum initial efficiency obtained is 8.97% with dual buffer which is 6.7% higher than that obtained by using conventional single buffer layer at the p/i interface. Stabilized efficiency of the cell with dual buffer is found to be ~9.5% higher than that with single buffer after 600h of light soakings.

In this paper we present the role of plasma excitation frequency and electsrode separation on the growth of microcrystalline silicon thin films at two different hydrogen dilutions of silane and different power densities. We optimized the process conditions to develop device quality microcrystalline material. Optoelectronic and structural properties of the developed material have been correlated with the solar cell properties. Growth rate ~7 Å/s has been achieved using plasma excitation frequency of 27.12 MHz at 15 mm electrode separation. We have noticed the positive effects after reducing the electrode separation in higher frequency (27.12 MHz). Optimized microcrystalline film of activation energy 0.55 eV and grain size of 14.61 nm has been developed and is applied to fabricate single junction microcrystalline solar cell. Solar cell with initial cell efficiency of 7.75% with short circuit current density of 24.98 mA/cm2 and open circuit voltage of 0.47 V and fill factor of 0.66 has been achieved.

At present main challenges of flexible thin film solar cell is its low initial efficiency. Use of suitable back reflector is one of the major ways of improving its performance. We synthesized ITO (Indium tin-oxide) nanoparticles by plasma treatment in a vacuum chamber using low pressure, high power technique at room temperature. We investigated the variation of size and shape of the nanoparticles with the process pressure, power density and process time and optimized it for solar cell application. Structural and optical characterization of the nanoparticles were carried out by FESEM and UV-VIS-NIR spectrophotometer. In this paper we introduce ITO nanoparticles as back reflector in silicon based thin film flexible solar cell. It has been found that by using suitable ITO nanoparticles it is possible to increase the solar cell short circuit current (Isc) by 8.9%. This may be due to the better light reflection from the back after application of nanoparticles. The maximum efficiency obtained with ITO nanoparticles back reflector is 8.27% which is 4.68% higher than that obtained without ITO nanoparticles at back.

In this paper, we have discussed about the development of high-quality n-μc-SiO:H films by a seeding technique working as a potential back reflector layer (BRL). Highly crystalline and conducting n-μc-Si:H films are used as a seed layer. Phosphorous-doped SiO$_x$:H film with suitable optoelectronics properties has been deposited by a radio frequency plasma enhanced chemical vapor deposition technique using parallel plate reactors (capacititively coupled). Optoelectronics properties have been controlled and optimized varying the deposition parameters such as process pressure, power density, partial pressure of CO2, etc. We have also innovatively replaced the n-layer, i.e., n-a-Si:H in case of the a-Si:H cell and n-μc-Si:H for μc-Si:H cells by this optimized seed + n-μc-SiO:H films. The performance of this n-μc-SiO:H film grown on the n-μc-Si:H seed layer as n-layer as well as BRL of single junction a-Si:H and μc-Si:H solar cells has been evaluated and better Photovoltaic (PV) characteristics of the solar cell are realized as compared to those of the films developed without any seed layer. a-Si:H solar cells with initial efficiency of 9.38% and μc-Si:H solar cell of 8.50% have been successfully fabricated by using improved doped SiO $_x$:H based BRL replacing conventional n-layer of the single junction cells.

The advantages of the amorphous silicon (a-Si)/crystalline silicon (c-Si) hetero junction technology are low temperature (<200 degrees C) processing and fewer process steps to fabricate the device. In this work, we used indium tin oxide (ITO) nanoparticles embedded in amorphous silicon material at the rear side of the crystalline wafer. The nanoparticles were embedded in silicon to have higher scattering efficiency, as has been established by simulation studies. It has been shown that significant photocurrent enhancements (32.8 m Lambda cm(-2) to 35.1 m Lambda cm(-2)) are achieved because of high scattering and coupling efficiency of the embedded nanoparticles into the silicon device, leading to an increase in efficiency from 13.74% to 15.22%. In addition, we have observed a small increase in open circuit voltage. This may be due to the surface passivation during the ITO nanoparticle formation with hydrogen plasma treatment. We also support our experimental results by simulation, with the help of a commercial finit-edifference time-domain (FDTD) software solution.

Light trapping is one of the fundamental necessities of thin film based solar cell for its performance elevation. Back reflection of unused light of first pass is the key way to improve the light trapping phenomena. In this study we have reported the development of n-type hydrogenated microcrystalline silicon oxide (n-µc-SiO:H) layers of different characteristics. The deposition has been done by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique. The detailed characterization of the films include the following: (1) electrical properties (2) optical properties like E04 (3) structural studies which include crystalline fraction by Raman spectroscopy and grain size by X-ray diffraction measurement, FTIR spectroscopy, AFM and TEM studies. n-µc-SiO:H layer has been introduced as the n-layer of single junction p–i–n structure µc-Si solar cells. By various techniques the optimum use of n-µc-SiO:H layer for enhancing the performance of µc-Si:H solar cells has been done. It has been found that by using suitable bilayer of two different n-µc-SiO:H layers, it is possible to increase the solar cell performances. The maximum efficiency obtained without any back reflector is 8.44% that is about 8.9% higher than that obtained by using n-µc-Si:H layer as n-layer in the solar cells.

In this paper, a novel method of preparation and systematic study of application of low-loss tin oxide (SnO2) nanospheres located at the rear side of crystalline silicon solar cells having partial rear contact have been presented. The improvement in efficiency due to light harvesting through optical scattering of tin oxide nanospheres is significant for thin silicon solar cells. Finite-difference time-domain (FDTD) simulations reveal that embedding of the rear-located nanospheres is necessary for back scattering of light from the rear surface. An analytical electrical model has been developed utilizing the results of optical simulations to estimate the solar cell parameters and efficiency enhancement of solar cells. The model shows that an absolute efficiency enhancement of ∼19% can be achieved for 16% efficient 10-μm thin silicon solar cell with partial rear contact. The enhancement is lower (∼6%) for thicker (180 μm) partial rear contact cells. Experimentally, SnO2 nanospheres have been synthesized and applied at the rear side of partial rear contact solar cell as a proof of experiment to validate the potential of this approach. A relative enhancement of short-circuit current by 2.3% and open-circuit voltage by 2.5% has been achieved experimentally for 180-μm silicon solar cells leading to 5.2% higher efficiency with respect to baseline efficiency validating this concept.

The modeling and analysis of recombination properties is one of the critical aspects in the design and development of high efficiency amorphous silicon (a-Si)/crystalline silicon (c-Si) heterostructure solar cell (SH-SC). In this paper, we have developed a recombination model pertinent for a-Si/c-Si SH-SC. Based on the model, an analytical expression for the relationship between effective carrier lifetime (τ eff ) and excess carrier concentration (An), commonly termed as lifetime curve, is derived and the results are validated with the experimental data. The results show that the inverse of τ eff , after correcting for the contributions of Auger and radiative recombination in silicon, when plotted as a function of An, shows a linear characteristic, with each of the slope and the intercept, providing definitive details about the recombination processes occurring in the device.

Hydrogenated microcrystalline silicon (mu c-Si:H) films play different types of roles in the fabrication of single and multi-junction amorphous silicon (a-Si)(center dot) solar cells and also act as an active layer in microcrystalline cells which forms the bottom cell of micromorph solar cells. The detailed study of doped microcrystalline layers have not been done properly and there is uncertainty about the role of n-microcrystalline layer on the performance of single junction a-Si solar cells (Poissant et al., 2003). In this paper we have reported the results of deposition of n-type hydrogenated microcrystalline silicon (n-mu c-Si:H) layers with different deposition parameters. The deposition has been done by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique at 13.56 MHz frequency. The detailed characterization of the films include the following: (1) electrical properties by activation energy, dark and photo conductivity, (2) optical properties like band gap and E-04 (3) structural studies which include crystalline fraction by Raman spectroscopy and grain size by X-ray diffraction and AFM, FE-SEM, TEM studies. The interpreted results are also presented.The n-mu c-Si:H layer has been introduced as the n-layer of single junction p-i-n structure a-Si solar cells. By various techniques the optimum use of n-mu c-Si:H layer for enhancing the performance of a-Si solar cells has been done. It has been found that by using suitable bilayer of n-mu c-Si:H layer/(thin) n-a-Si:H layer it is possible to increase the fill factor of the solar cell by 5%. This may be due to the higher conductivity of the n-mu c-Si:H layer and the quality of intrinsic layer. It is also possible to increase the open circuit voltage by 3.3%. The maximum efficiency obtained without back reflector is 9.46% that is about 14.3% higher than that obtained by using n-a-Si:H layer as n-layer in the solar cells. (C) 2015 Elsevier Ltd. All rights reserved.

This paper discusses the prospect of using indium tin oxide (ITO) nanoparticles as back scatterers in crystalline silicon solar cells instead of commonly used metal nanoparticles as ITO nanoparticles have comparatively low dissipative losses and tunable optical properties. ITO nanoparticles of similar to 5-10 nm size is developed on the rear side of the solar cell by deposition of 5-10 nm thick ITO layer by DC magnetron sputtering followed by hydrogen treatment in PECVD. The silicon solar cell is fabricated in the laboratory using conventional method with grid metal contact at the back surface. Various characterizations like FESEM, TEM, AFM, XRD, EQE and IV characteristics are performed to analyze the morphology, chemical composition, optical characteristics and electrical performance of the device. ITO nanoparticles at the back surface of the solar cell significantly enhances the short circuit current, open circuit voltage and efficiency of the solar cell. These enhancements may be attributed to the increased absorption and carrier collection at longer wavelengths of solar spectrum due to enhanced light trapping by the ITO nanoparticles and surface passivation by the hydrogen treatment of the back surface. (C) 2015 Elsevier B.V. All rights reserved.