N-type Si Research Articles

Detailed investigation of electrical and optical properties of textured n-type and roughened p-type tunnel oxide passivated contacts for screen-printed double-side passivated contact silicon solar cell application

This paper presents detailed characterization and analyses of the optical, electrical, and contact properties of a 35 nm phosphorus-doped (n-type) polysilicon (poly-Si) and a 250 nm boron-doped (p-type) poly-Si deposited respectively on textured and roughed surface. These layers could be applied respectively to the front and rear sides of an n-type Si to produce back junction bifacial screen-printed double-side tunnel oxide passivated contacts (DS-TOPCon) solar cells. Optical and device modeling revealed a short circuit current density loss of 1.5 mA/cm2 and 0.5 mA/cm2 due to absorption in the front n-TOPCon and rear side p-TOPCon layers, respectively. The passivation and contact properties including metalized and unmetallized recombination current density (J0), as well as contact resistivity, were determined as a function of contact firing temperature in the range of 700∼800℃. The passivation quality of the front thin n-TOPCon was found to deteriorate with increased firing temperature while the rear thick p-TOPCon improved. The study showed that the simulated contact firing at 730℃ resulted in the best unmetallized double-side TOPCon precursor, with an excellent implied open-circuit voltage of 730 mV and implied fill factor of ∼86 %. However, the metalized J0 increased and contact resistivity decreased monotonically with the increase in the firing temperature. The 2D device simulations revealed that these layers can produce screen-printed DS-TOPCon cells with an efficiency of ∼22.5 %. Solar cell modeling also showed that the DS-TOPCon solar cell efficiency can reach 24.1 % by decreasing the n-TOPCon thickness to 20 nm and lowering the full area metalized J0 to ∼100 mA/cm2.

X-Ray Diffraction and Raman Spectroscopy Analyses of GaSb-Enriched Si Surface Formed by Applying Diffusion Doping Technique

The paper studies the properties of surface and near-surface region of a single crystalline silicon sample doped with atoms of Ga (AIII) and Sb (BV). n-type single-crystal Si wafers were chosen as substrates, and samples were size of 8×10×0.5 mm3. For diffusion into silicon, Ga and Sb impurities were used with a purity of 99.999 and 99.998, respectively. The authors propose that a new heterostructure might form in the near-surface region of silicon that could be engineered by applying a relatively cheap diffusion method. The experimental and analysis results show that the composition and absorption spectrum of silicon start manifest certain changes, and can be used in the future as a functional material for solar cells. The result showed that randomly located islands with an average diameter of 1–15 µm are formed on the substrate surface. X-ray diffraction analysis was carried out using a Rigaku diffractometer to study the crystallographic parameters of islands formed with the participation of Ga and Sb atoms on the silicon surface. The energy spectrum was studied on Nanofinder High End Raman spectrometer (LOTIS TII) in order to determine the presence of complexes of Ga and Sb atoms within islands formed as a result of diffusion. The optical emission spectra in the new structure were studied using a Lambda 950 spectrophotometer. The measurements were carried out at room temperature, i.e., at 300°K. Having studied the results of X-ray analysis, Raman spectroscopy, and optical spectroscopy, the authors have revealed that Ga and Sb atoms form new Si0.44(GaSb)0.56 and Si0.75(GaSb)0.25-type binary compounds on Si surface.

Improvement of passivation performance of silicon nanocrystal/silicon oxide compound layer by two-step hydrogen plasma treatment

A two-step hydrogen plasma treatment (HPT) is carried out for Si nanocrystals/silicon oxide compound passivating contacts to improve their passivation performance. The 2-step HPT consists of a first HPT at a high temperature of 500 °C and a second HPT at a lower temperature of 300 °C. Etching of n-type polycrystalline Si (n+-poly-Si) is suppressed by using low RF power and short duration as the condition for the second HPT. For the passivating contact with thin n+-poly-Si, the implied open-circuit voltage (i-VOC) was improved to 723 mV after the 2-step HPT, which is higher than the i-VOC after the one-step HPT (718 mV) owing to enhanced hydrogenation of the Si nanocrystals/silicon oxide compound layer. On the other hand, 1.4-fold larger contact resistivity (ρc) was obtained after the 2-step HPT. This increase in ρc is probably attributed to the suppression of trap-assisted tunneling. The largest i-VOC value of 744 mV and the lowest ρc value of 12 mΩ cm2 was observed for the contact with 300-nm-thick n+-poly-Si, possibly due to enhanced field-effect passivation after the 2-step HPT.

Employment of Silicon Nitride Films Prepared by DC Reactive Sputtering Technique for Ion Release Applications

In this work, silicon nitride (Si3N4) thin films were deposited on metallic substrates (aluminium and titanium sheets) by the DC reactive sputtering technique using two different silicon targets (n-type and p-type Si wafers) as well as two Ar:N2 gas mixing ratios (50:50 and 70:30). The electrical conductivity of the metallic (aluminium and titanium) substrates was measured before and after the deposition of silicon nitride thin films on both surfaces of the substrates. The results obtained from this work showed that the deposited films, in general, reduced the electrical conductivity of the substrates, and the thin films prepared from n-type silicon targets using a 50:50 mixing ratio and deposited on both surfaces of a titanium substrate reduced the electrical conductivity of this substrate by 30%. This reduction in the release of ions from the coated metal substrate is attributed to the dielectric properties of the deposited silicon nitride thin films. This result is very important and applicable. This work represents the first attempt in Iraq to study such effects and may represent a good starting point for advanced studies in biomedical engineering.

Rechargeable Silicon-Ion Batteries

Silicon (Si) is the second abundant material in nature and yet, despite its high abundance and ease of production, the possibility of using Si as an active multivalent rechargeable anode was never explored or reported. As a proof of concept, we will discuss in this talk a new rechargeable Si-ion cell, its design and architecture, enabling Si to be reversibly discharged at 1.1 V and charged at 1.5 V. Several discharge-charge cycles were achieved, utilizing heavy doped n-type Si wafer anodes, and hybrid based ionic liquid electrolytes. In addition, dissolved halides are functioning as conversion cathodes. Cell characterizations correlated the discharge and charge processes with the presence of dissolved fluoride and Si species in the electrolyte. The presence of appreciable fluoride species is crucial in both establishing surface activation and battery operation, and their depletion is directly linked to cell performance degradation. We will discuss Si ions deposition and dissolution mechanisms.

Versatility Investigation of Grown Titanium Dioxide Nanoparticles and Their Comparative Charge Storage for Memristor Devices.

Memristive devices have garnered significant attention in the field of electronics over the past few decades. The reason behind this immense interest lies in the ubiquitous nature of memristive dynamics within nanoscale devices, offering the potential for revolutionary applications. These applications span from energy-efficient memories to the development of physical neural networks and neuromorphic computing platforms. In this research article, the angle toppling technique (ATT) was employed to fabricate titanium dioxide (TiO2) nanoparticles with an estimated size of around 10 nm. The nanoparticles were deposited onto a 50 nm SiOx thin film (TF), which was situated on an n-type Si substrate. Subsequently, the samples underwent annealing processes at temperatures of 550 °C and 950 °C. The structural studies of the sample were done by field emission gun-scanning electron microscope (FEG-SEM) (JEOL, JSM-7600F). The as-fabricated sample exhibited noticeable clusters of nanoparticles, which were less prominent in the samples annealed at 550 °C and 950 °C. The element composition revealed the presence of titanium (Ti), oxygen (O2), and silicon (Si) from the substrate within the samples. X-ray diffraction (XRD) analysis revealed that the as-fabricated sample predominantly consisted of the rutile phase. The comparative studies of charge storage and endurance measurements of as-deposited, 550 °C, and 950 °C annealed devices were carried out, where as-grown device showed promising responses towards brain computing applications. Furthermore, the teaching-learning-based optimization (TLBO) technique was used to conduct further comparisons of results.

Effect on passivation mechanism and properties of HfO2/crystalline-Si interface under different annealing atmosphere

Hafnium oxide (HfO2) thin film has received tremendous research interests as a passivation layer of crystalline silicon (c-Si) due to its thermal stability and positive fixed charges. HfO2 films were prepared both on P-type and N-type polished c-Si via a remote plasma atomic layer deposition process. Post annealing was carried out in oxygen, atmosphere (Air) and nitrogen (N2) at temperature of 500 °C. Electrical characterization was done through a regular metal-insulator-semiconductor structure and capacitance-voltage measurements. The oxide fixed charge (Qf) and density of interface traps (Dit) between HfO2 and c-Si were extracted. Qf and Dit reveal the potential of HfO2 for field effect and chemical passivation, respectively. Effective lifetime measurements by microwave photoconductivity decay in Si wafers passivated with HfO2 were applied to characterize surface recombination velocity to directly evaluate the overall passivation quality. The impacts of post-annealing gas ambient on passivation qualities on Si by HfO2 thin films are systematically studied. The results show that N2-annealed sample possesses the highest Qf of 1.73 × 1012 cm−2 and therefore provides the best field effect passivation. Air-annealed sample has lowest Dit of 1.0 × 1012 eV−1cm−2 and therefore provides the best chemical passivation. Air-annealed sample possesses the highest effective lifetime of 290 μs at injection level of 1 × 1015 cm−3, which means that good passivation was obtained for N-type Si wafer passivated with HfO2 after annealing in Air.

Phosphorus-doped silicon copper alloy composites as high-performance anode materials for lithium-ion batteries

Silicon (Si) anodes are considered one of the most promising candidates for next-generation lithium-ion batteries, owing to their high theoretical capacity. However, Si-based anodes suffer from significant volume expansion during lithiation, leading to severe mechanical degradation and poor cycling stability. To address these challenges, We developed phosphorus (P)-doped Si-Cu alloy composites via a simple vacuum melting method. The incorporation of Cu3Si in the composites effectively suppressed the volume expansion of Si, while P doping enabled the formation of N-type Si to improve electrical conductivity. In our study, we conducted a comprehensive analysis of the electrochemical performance of the P-doped Si-Cu alloy composites. Among the samples, the P0.5% Si-Cu alloy composite exhibited the most exceptional electrochemical performance, with a capacity of 1048 mAh/g after 60 cycles at the current density of 100 mA/g. Electrochemical impedance spectroscopy (EIS) measurements revealed a lower Rct value of 73.65 Ω for the P0.5% Si-Cu alloy composite compared to 175.2 Ω for the Si-Cu alloy composite. Our theoretical calculations also demonstrated that P doping reduces the energy barrier for lithium-ion diffusion. Our study validated the potential of P-doped Si-Cu alloy composites as high-performance anode materials for lithium-ion batteries and provides new insights into the design of Si-based anodes with improved stability and cycling performance.

SiOx/polysilicon selective emitter prepared by PECVD-deposited amorphous silicon plus one-step firing enabling excellent J0,met of < 235 fA/cm2 and ρc of < 2 mΩ·cm2

Boron(B)-doped polysilicon (poly-Si) is the key element to achieve high efficiency and low-cost bifacial tunnel oxide passivated contact (TOPCon) silicon solar cells. In this work, we explore the feasibility of using a plasma-enhanced chemical vapor deposition (PECVD) system to prepare the high-performance poly-Si fingers as selective emitters (poly-finger SE) through depositing nano SiOx and B-doped amorphous silicon plus one-step annealing process. It is found that the poly-finger SE not only reduces the recombination current density under metal contacts (J0,met) from ∼ 1300 fA/cm2 to ∼ 230 fA/cm2, while maintaining a low contact resistivity (ρc) of ∼ 1.6 mΩ·cm2. Additionally, numerical simulations indicate that n-type Si solar cells with poly-finger SE can achieve a high efficiency of 25.36% based on the most advanced device manufacturing technology and the above-mentioned passivation and contact performances. The open-circuit voltage (Voc) increased by 11.1 mV and 4.8 mV compared to controlled and laser SE TOPCon solar cells, manifesting the efficiency increase of 0.39% and 0.20%. Overall, this work presents a new method to enhance the efficiency of TOPCon devices.

Temperature dependency of electronic and optoelectronic performance of 2,4-Bis[4-(N,N-dibenzylamino)-2,6-dihydroxyphenyl]squaraine/n-Si organic/inorganic heterojunction for photovoltaic application

The potential of squaraine dyes in solar cells lies in their ability to strongly absorb in the visible and near-infrared regions, as well as their high molar absorptivity. Vacuum deposition was used to prepare a heterojunction (HJ) of 2,4-Bis[4-(N,N-dibenzylamino)-2,6 dihydroxyphenyl]squaraine dye (SQ) thermally deposited onto n-type Si wafer. The SQ film was analyzed using atomic force microscopy, which revealed an average grain size of 35 nm. X-ray diffraction procedure was applied to recognize the internal crystal structural properties of the SQ film deposited onto n-type Si wafer, showing that it has a nanostructure with a crystal size of 23 nm. The absorption study revealed that the SQ film has two band gaps, measuring 1.71 and 2.23 eV. The electronic properties of the SQ/n-Si HJ were analyzed under varying temperatures (298–378 K) in dark conditions. The current density-voltage (J-V) and capacitance-voltage (C–V) procedures were applied to extract the diode parameters of SQ/n-Si HJ, which displayed temperature-dependent behavior. The SQ/n-Si HJ exhibited photovoltage conductivity under light, allowing for the evaluation of photovoltaic parameters. At room temperature, 7.596 mA/cm2, 0.625 V, and 2.04% corresponding to photovoltaic parameters of SQ/n-Si HJ were obtained for short-circuit current (Jsc), open-circuit voltage (Voc) and power conversion efficiency (PCE%), respectively. However, it was observed that these photovoltaic parameters decreased as the temperature increased. These findings suggest that the SQ/n-Si HJ has the potential for utilization in photovoltaic devices.

The impact of oxygen partial pressure in modifying energy storage property of lanthanum doped multiferroic bismuth ferrite thin films deposited via pulsed laser deposition

Lead-free dielectric thin films' potential as pulse capacitors in power electronic devices has garnered attention to their energy storage usage. The current study aims at the growth of multiferroic thin films using the pulsed laser deposition technique for energy storage capacitor applications. Under various OPPs, single-phase La-doped bismuth ferrite (Bi0.993La0.007FeO3) BLFO thin film of 200 nm thickness is deposited on quartz and n-type Si substrates (15 to 30 SCCM). The crystal planes (110) and (006) of the rhombohedral phase with space group R3c are confirmed by high-resolution HRTEM and SAED patterns that augmented the XRD analysis. The optimized films have a smooth, uniform microstructure with 3 nm root-mean-square (RMS) roughness. The film shows an enhanced dielectric constant of 447 at room temperature with an improved ferroelectric property. At 488 kV/cm, the 20 SCCM BLFO films achieved 78.42 % energy efficiency and 2.09 J/cm3 energy density. The same films also exhibited a lower value of bandgap energy, confirming the strong absorption at 452 nm wavelength. The relatively high refractive index of 2.78 is determined for the same film suggesting the higher crystallinity of the film. Further, the low magnitude of leakage current density of the grown film is ∼10−7 A/cm2 at ±100 kV/cm. Though achieving the pure phase and fabricating BLFO thin films is challenging, these results are appropriate for the thin films to realize as energy storage capacitor applications.

Enhanced magnetic properties and leakage current mechanism in bismuth lanthanum ferrite thin films coupled with impedance and magnetic studies

A highly crystalline and pure phase Bi0.993La0.007FeO3 (BLFO) thin films have been grown using a pulsed laser deposition technique. The structural analysis confirmed the thin film is well crystallized with a rhombohedral crystal structure with an R3c space group. The BLFO phase and composition are also confirmed by transmission electron microscopy and EDAX analysis. The surface chemistry of thin films, analysed by X-ray photon spectroscopy, reveals Fe's presence in Fe3+ and Fe2+ states. At RT, the deposited film exhibited high dielectric permittivity (∼4 × 102) and low dielectric loss (∼10−1). The isothermal magnetization on highly oriented (001)-MgO and LaAlO3 (LAO) substrates is investigated. The response is compared to the randomly oriented polycrystalline films on low-cost substrates (Pt/TiO2/SiO2/Si and n-type Si substrate). The enhanced saturation magnetization of 57 emu/cm3 and 36 emu/cm3 at 10 K and 300 K are observed at 2.5 kOe applied field for the film grown on the LAO substrate. Additionally, the low leakage current density of the film is obtained around ∼1 × 10−7 A/cm2 at a field of 100 kV/cm. Acquiring single-phase BLFO thin films with enhanced electrical and magnetic properties can be relevant in designing multiferroic materials for multiple-state memories, magnetic field sensors, and spintronics applications.

A Wide Frequency Range C-V and G-V Characteristics Study in Schottky Contacts with a BODIPY-Pyridine Organic Interface

In this study, it was aimed to produce an organic interface layered Schottky diode structure and frequency effect on capacitance-conductance-voltage measurements. In this context, phosphor doped n-type Si single crystal has been used as a semiconductor substrate with a 1-20 Ω.cm resistivity, (100) surface oriention, 2 inches in diameter and 350 μm thickness. The (E)-5,5-difluoro-1,3,7,9-tetramethyl-10-phenyl-2-(2-(pyridin-2-yl)vinyl)-5H-54,64-dipyrrolo [1,2-c:2',1'-f] [1,3,2] diazaborinine (BODIPY-Pyridine) thin film was coated on n-Si using the spin coating technique.&#x0D; Ohmic and rectifier contacts were coated by evaporation of indium (In) and gold (Au) using a thermal evaporation system and Au/ BODIPY-Pyridine/n-Si/In Schottky diode was fabricated. Capacitance-voltage (C-V) and conductance-voltage (G-V) measurements of this structure were gained at different frequencies in the dark. Contingent on the frequency, the series resistance (Rs) and the interface state density (Nss) values were identified by using the conductance and Hill-Coleman method, respectively.

Direct-current output of silicon–organic monolayer–platinum Schottky TENGs: Elusive friction-output relationship

Triboelectric nanogenerators (TENGs) are an emerging energy harvesting technology able to convert ubiquitous mechanical energy into electricity. Friction, static charging and flexoelectricity are all involved in the mechanism underpinning TENG operation, but their relative contribution has remained elusive. Here we used dynamic and static conductive atomic force microscopy (C-AFM) measurements on monolayer-modified silicon crystals to detect evidence of a relationship between friction and zero-bias current, and between pressure and the direction of the putative flexovoltage. We demonstrate that a static electricity-related tribovoltage is probably responsible for a friction excess, and that surprisingly this friction excess is found to be dependent on the doping level and type of the silicon substrate. Such friction excess is however no longer measurable once current is allowed to flow across the junction. This observation points to an electrostatic origin of friction in silicon-based Schottky TENGs, and suggests that the zero external bias DC current is at least in part an electronic flow to neutralize static charges. Further, the sign of the zero-bias current, but not its magnitude, is independent of the semiconductor doping type, which is again suggestive of surface statics being a main contributor to the zero-bias output rather than exclusively a space-charge effect. We also reveal the presence of a junction flexovoltage under pressures common in AFM experiments (GPa), even for negligible lateral friction. In a static Pt–monolayer–n-type Si junction the flexovoltage carries the same sign as the tribovoltage, and can reach such magnitude to overwrite external voltages as high as 2 V. The immediate implication is that the flexovoltage is likely to have i) a strong contribution to the zero-bias output of a n-Si Schottky TENG, ii) a negative effect on the output of a p-Si TENG, and iii) its detection can be straightforward, as we discovered that flexoelectricity manifests as an “inverted diode”: a n-type Si–platinum diode with negligible current even when the n-type material is negatively biased as long as the “static” diode remains under a large normal pressure.

Nonvolatile resistive switching in lead-free La2CoMnO6-based memory device

Dense and flat La2CoMnO6 films as the resistive switching functional layer were deposited on n-type Si substrates by sol–gel method. Excellent bipolar resistive switching performance was observed in the Au/La2CoMnO6/Si device for the first time. The high and low resistance states with a ratio of ∼105 could be maintained for more than 1.4 × 104 s and 750 cycles without significant degradation at room temperature. The bipolar resistive switching effect could be sustained within a wide temperature range of 220 K∼300 K. Electrical conduction analysis indicated that the resistive switching behavior in La2CoMnO6 films was primarily controlled by space-charge-limited current mechanism which originated from the change of oxygen vacancies. Density functional theory calculations indicated that the conductive ability of La2CoMnO6 films was promoted with increasing concentration of oxygen vacancies. Moreover, it is found that the modulation of the barrier located at the Au/La2CoMnO6 interface was responsible for the resistive switching under applied bias voltages.

INVESTIGATION OF STRUCTURAL, OPTICAL, AND ELECTRICAL PROPERTIES OF ITO FILMS DEPOSITED AT DIFFERENT PLASMA POWERS: ENHANCED PERFORMANCE AND EFFICIENCY IN SHJ SOLAR CELLS

This article presents an investigation into the structural, optical, and electrical properties of Indium Tin Oxide (ITO) films that were deposited utilizing various plasma powers. The transmittance values in the visible region were measured, revealing that the ITO film deposited at 2050 W exhibited the highest transmittance (81%). Additionally, the sheet resistance values of all films were analyzed, indicating that the ITO film deposited at 2050 W had the lowest sheet resistance (64.9 Ω/sq). By means of XRD analysis, the structural properties of the films were meticulously scrutinized, and the distinctive diffraction peaks associated with the ITO films were successfully identified. Notably, the ITO film deposited at 2050 W demonstrated superior performance compared to the other films deposited using various plasma powers. Finally, we report a noteworthy efficiency of 17.03% achieved in the SHJ solar cell fabricated with the ITO film deposited at 2050 W on a 5x5 cm2 n-type Si substrate.

Effect of Annealing Temperature on the Structure and Properties of La2O3 High-K Gate Dielectric Films Prepared by the Sol-Gel Method

This article presents the sol-gel method for depositing La2O3 thin films on n-type Si substrates and quartz substrates, and investigates the impact of annealing temperature on the microcomposition, surface morphology, optical properties, and band characteristics of the films. X-ray diffraction (XRD) analysis indicates that the films are amorphous below 500 °C, with annealing resulting in a hexagonal-phase La2O3 (h-a2O3) and new non-hydrated impurities. Fourier-transform infrared (FTIR) analysis reveals that the prepared La2O3 film is unaffected by moisture. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) provide evidence that the La2O3 film has a smooth, uniform surface without cracks. The roughness increases from 0.426 nm to 1.200 nm, and the film thins from 54.85 nm to 49.80 nm as the annealing temperature rises. The film’s transmittance is above 75%, as measured by UV-Vis, and the calculated optical bandgap increases from 5.11 eV to 5.75 eV. The calculated band offset of the La2O3 film is greater than 1 eV, which meets the minimum requirements for MOS devices, thus providing promising prospects for La2O3 films in MOS applications.

On/Off Ratio of a Pentacene Field-Effect Transistor with a Discontinuous MoO&lt;sub&gt;3&lt;/sub&gt; Layer

Improvement of the on/off ratio in organic field-effect transistors through the use of pentacene and molybdenum trioxide (MoO3) layers was attempted via the preparation of a discontinuous MoO3 layer using a mesh mask. We prepared three types of devices. Device A had a conventional top-contact structure with an n-type Si wafer and a 200-nm-thick SiO2 film onto which we deposited a 70-nm-thick pentacene film and a 30-nm-thick layer of Au top electrodes. Devices B and C had a similar structure to device A but received a continuous and a discontinuous MoO3 layer, respectively. The off current in Device B was remarkably high; in contrast, the off current in Device C was reduced and dependent on the separation of the MoO3 layer. It was deduced that the high resistance of the area without MoO3 contributed to the reduced off current.

Charge trapping effect at the interface of ferroelectric/interlayer in the ferroelectric field effect transistor gate stack

We study the charge trapping phenomenon that restricts the endurance of n-type ferroelectric field-effect transistors (FeFETs) with metal/ferroelectric/interlayer/Si (MFIS) gate stack structure. In order to explore the physical mechanism of the endurance failure caused by the charge trapping effect, we first establish a model to simulate the electron trapping behavior in n-type Si FeFET. The model is based on the quantum mechanical electron tunneling theory. And then, we use the pulsed I d–V g method to measure the threshold voltage shift between the rising edges and falling edges of the FeFET. Our model fits the experimental data well. By fitting the model with the experimental data, we get the following conclusions. (i) During the positive operation pulse, electrons in the Si substrate are mainly trapped at the interface between the ferroelectric (FE) layer and interlayer (IL) of the FeFET gate stack by inelastic trap-assisted tunneling. (ii) Based on our model, we can get the number of electrons trapped into the gate stack during the positive operation pulse. (iii) The model can be used to evaluate trap parameters, which will help us to further understand the fatigue mechanism of FeFET.

On the passivation performance of SiNx, SiOxNy and their stack on c-Si wafers for solar cell applications: Correlation with optical, chemical and interface properties

SiNx and SiOxNy layers deposited by the PECVD method are commonly used in silicon solar cells for their excellent thin film properties. In this study, we perform an experimental analysis of the optical, chemical and electrical properties of these films prepared under different process conditions. The C–V measurements for the interface analysis reveal that SiOxNy layers for any refractive index have lower interface state density and fixed charge density than SiNx layers. Additionally, our calculations on the FTIR spectra indicate that SiNx, when compared with SiOxNy, has a significantly higher hydrogen amount which is important in reducing the interface traps. Furthermore, we explain the passivation results obtained from PCD measurement for single SiNx, single SiOxNy and their stack layers on p-type and n-type Si wafers by C–V and FTIR measurements. Our results suggest that depositing a very thin SiOxNy having low Dit beneath SiNx having high Qf and H amount provides superior passivation on p and n-type Si wafers, which is improved further by a subsequent fast-firing process.