Chemical Etching Method Research Articles

Dry Phosphorus silicate glass etching and surface conditioning and cleaning for multi-crystalline silicon solar cell processing

As an alternative to the wet chemical etching method, dry chemical etching processes for Phosphorus silicate glass [PSG} layer rel11ova] using Tri?uormethane/Sulfur Hexafluoride (CHF3/ SF6) gas mixture in commercial silicon-nitride plasma enhanced chemical vapour deposition (SiN-PECVD) system is applied. The dependence of the solar cell performance on the etching temperature is investigated and optimized. It is found that the SiN-PECVD system temperature variation has a signi?cant impact on the whole solar cell characteristics. A dry plasma cleaning treatment of the Si wafer surface after the PSG removal step is also investigated and developed. The cleaning step is used to remove the polymer ?lm which is formed during the PSG etching using both oxygen and hydrogen gases. By applying an additional cleaning step, the polymer ?lm deposited on the silicon wafer surface after PSG etching is eliminated. The effect of different plasma cleaning conditions on solar cell performance is investigated. After optimization of the plasma operating conditions, the performance of the solar cell is improved and the overall gain in ef?ciency of 0.6 % absolute is yielded compared to a cell without any further cleaning step. On the other hand, the best solar cell characteristics can reach values close to that achieved by the conventional wet chemical etching processes demonstrating the effectiveness of the additional O2/H2 post cleaning treatment.

No-core fiber interferometry pH sensor based on a polyvinyl alcohol/polyacrylic acid and silica/polyvinyl alcohol/polyacrylic acid hydrogel coating.

In this paper, we present an investigation on the sensing performance of a pH sensor based on a modal interferometer formed by a simple NO-core fiber interferometer (NCFI) that operates in transmission mode. The fundamental configuration of this sensor encompasses a single-mode-no-core-single-mode fiber (SMF-NCF-SMF "SNCS") segment chain. The chemical etching method has been used with hydrofluoric (HF) acid to prepare diverse NCF diameters. This was proposed to expand the evanescent fields and enhance sensor sensitivity. Then, the two diverse segments of etched NCF were cladded with polymeric composite fabricated by polyvinyl alcohol/polyacrylic acid (PVA/PAA) hydrogel and pure silica nanoparticles embedded in polyvinyl alcohol/polyacrylic acid (SiO2@PVA/PAA) hydrogel, respectively, for more sensing enhancement. Our results reveal that the PAA/PVA coating is a candidate coating material for acidic sensing, while SiO2@PVA/PAA is more appropriate for the base sensing, in which these coating materials show enhancement in the sensitivity above the NCF structure before an uncoated sensor due to greater enhancement of the evanescent field affected by the coating layer. The experimental results demonstrate a high average sensitivity of 3.42 nm/pH unit for the 11 w.t.% PVA/PAA coated sensor in the pH range from 1 to 7 and 3.2 nm/pH unit in the pH range from 8 to 14. The sensor also displays high repeatability and stability and low cross-sensitivity to temperature. The simple fabrication and high sensitivity of this sensor may prompt many potential applications in the fields of biology and chemistry.

Integration of Fe3O4 nanospheres and micropyramidal textured silicon wafer with improved photoelectrochemical performance

Silicon (Si)-based composites have attracted extensive attention for photoelectrochemical (PEC) application. Herein, micropyramidal textured Si wafer was constructed by wet chemical etching method. Hydrothermally synthesized Fe3O4 nanospheres were further deposited on the micropyramids by a simple dip-coating approach. The integrated Fe3O4 nanospheres and Si micropyramids (denoted as Fe3O4@SiMPs) revealed 20 times of higher PEC efficiency than planar Si wafer, without obvious photocurrent decay and crystalline structure change during chronoamperometry test. The greatly enhanced PEC performance of Fe3O4@SiMPs is largely attributed to the seamless integration of Si micropyramids and Fe3O4 nanospheres. The micropyramidal textured structure can enhance light absorption by reducing the surface reflectance and enhancing the light trapping effect. The micropyramids and Fe3O4 nanospheres on the surface of planar Si wafer offer more specific surface area for the contact of electrode with electrolyte. The Fe3O4 nanospheres not only protect the micropyramids from corrosion, but also accelerate the PEC kinetics by promoting charge transfer between the electrode and the electrolyte. This study can inspire the optimal design of Si wafer-based nanocomposites as efficient PEC catalysts for overall water splitting.

Folic Acid Coordinated Cu-Co Site N-Doped Carbon Nanosheets for Oxygen Reduction Reaction.

The design and development of carbon materials with high-efficiency oxygen reduction activity is still a problem. Folic acid (FA) has unique structural characteristics, and it can provide multiple coordination sites for metal ions. Here, folic acid (FA) was used as a metal complex ligand, and Cu-Co-based N-doped porous carbon nanosheets (Cu-CoNCNs) were synthesized by the solvothermal method, the molten salt template-assisted calcination method, and the chemical etching method. The Cu-CoNCNs synthesized by this method have highly efficient oxygen reduction reaction (ORR) activity. In 0.1 mol/L KOH electrolytes, the catalyst exhibits excellent ORR activity and has a fairly high half-wave potential (0.905 V vs reversible hydrogen electrode (RHE)). X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, infrared spectroscopy, and X-ray diffraction (XRD) were used to investigate the reasons why the catalyst has excellent catalytic activity and long-life stability. It was proved that the impressive ORR activity of Cu-CoNCNs comes from Cu doping, which can regulate the surface electronic structure of the catalyst, thereby optimizing the binding ability between the intermediate and adsorbed species and improving the catalytic activity.

Influence of H2O2 concentration on the structural and photoluminescent properties of porous silicon nanowires fabricated by metal-assisted chemical etching

Porous silicon nanowires (PSi NWs) are a promising material for applications in sensorics, photovoltaics, and biomedicine. However, the structural and optical properties of PSi NWs are extremely sensitive to the concentrations of chemical solutions used in their manufacture. In this study, PSi NWs were fabricated by a two step metal-assisted chemical etching method from highly doped crystalline silicon wafers with a resistivity of <0.005 Ω cm. It was shown that the structural and optical properties of the obtained samples depend on the concentration of hydrogen peroxide (H2O2), which in our experiments varied from 5 to 30%. As a result of etching, a layer of NWs with a diameter of 50–200 nm is obtained from above, and a thin layer of porous silicon is obtained from below. The ratio of the thicknesses of these two layers can be tuned by choosing the required concentration of H2O2. The porosity of the samples, calculated in the approximation of the effective Bruggeman medium from the IR reflection spectra, was 40–50%. Electron microscopy demonstrated the presence of a large amount of silicon nanocrystals in the volume of PSi NWs, which exhibited efficient visible photoluminescence due to quantum confinement effect. It was shown that the size of the nanocrystals can be also tunable on the used concentration of H2O2.

Preparation of Adiabatic Microfiber Bragg Grating by Chemical Etching

Micro fiber Bragg grating (MFBG) is sensitive to temperature and refractive index at the same time, and has excellent sensing performance. Scholars all over the world have carried out a lot of research on it. At present, for the preparation of adiabatic MFBGs, micro fibers meeting adiabatic conditions are prepared by heating stretching method, and then fabricated by mask method or etching method. In order to simplify the preparation process, based on chemical etching method, a simple and easy technique for preparing adiabatic MFBG is proposed. In this technique, the FBG immersed in corrosion solution is gradually lifted by stepping motor, which can form a transition region with decreasing diameter, so that the cone angle of the transition region meets the adiabatic conditions, and then an adiabatic MFBG is formed. Several adiabatic MFBGs with different diameters are actually fabricated. The results show that adiabatic MFBG has better spectral and wavelength stability than ordinary MFBG. Finally, the refractive index and temperature sensing of the MFBGs are realized, the results showed that for MFBG with a diameter of about 9 μm, its sensing sensitivity to refractive index and temperature are 5200 pm/RIU and 10.06 pm/°C, for MFBG with a diameter of about 12 μm, the sensing sensitivity are 1125 pm/RIU and 10.33 pm/°C.

Novel technique for large area n-type black silicon solar cell by formation of silicon nanograss after diffusion process

Metal-assisted chemical etching (MACE) method is the most convenient and cost-effective nanowire fabrication method compared to other nanowire fabrication processes although a major problem arises in silicon nanowire, formed by MACE solution during n-type c-Si solar cell fabrication steps. High-temperature boron diffusion in conventional open tube furnace breaks down the nanowire resulting in a non-uniform surface pattern which is responsible to decrease overall conversion efficiency of the finished cell. In this work, this drawback is resolved by considering silicon nanowire formation after diffusion step. A slow etchant is considered for nanostructure on diffused silicon wafer to protect the diffused junction. The generated nanowire size is very less and has forage-like structure, and so termed as nanograss. Surface morphology and the characterization of the silicon nanograss structure after diffusion process on large area (156 mm × 156 mm) c-Si solar cells using MACE method have been investigated elaborately. Further, the complete solar cell has been fabricated with an efficiency of 17.20%.

Band gap modification for enhancement in optoelectronic properties with silicon nanowire

Here, by varying the etching time of Si wafer with metal-assisted chemical etching process, we have formed the vertically aligned silicon nanowire (VA-SiNW) by etching the Si wafer for the duration of 40 min with metal-assisted chemical etching method. In this study Field-effect scanning electron microscopy has been used for the characterization of VA-SiNW (FESEM). Here the etching duration of 40 min has been used, the band gap modification has been analyzed by the use of photoluminescence spectroscopy. The study of photoluminescence spectroscopy (PL) and XRD offers proof of our findings and appears as supporting information. These 1-D nanostructures are quite influential in sensing, biological applications anti-reflection coating (ARC) properties and have broad use in electronic field.

High-capacity CVD-grown Ge nanowire anodes for lithium-ion batteries: simple chemical etching approach for oxide removal

We demonstrated high-performance Ge nanowire (NWs) anodes for rechargeable lithium-ion batteries with high-capacity and high coulombic efficiency. The NWs were prepared using a simple chemical vapor deposition (CVD) method, which is favorable for the mass production of electrodes. The unstable oxides of Ge deteriorate the electrochemical characteristics of the batteries made from Ge-based anodes. To resolve the issue of the oxides and enhance the electrochemical performance, the oxides of the NWs were removed efficiently by a simple wet chemical etching method via a 10% HCl (aq) treatment. Transmission electron microscopy and energy-dispersive X-ray spectroscopy elemental mapping verified the removal of oxides. Charge and discharge capacity of the pristine NWs were 833.803 mAhg−1 and 650.63 mAhg−1 at first cycle. In comparison, the charge and discharge capacities after oxide removal were 1064.1 mAhg−1 and 905.6 mAhg−1 under the same conditions. The discharge capacity and coulombic efficiency of the oxide-removed NWs were 39.2% and 7.1% higher than those achieved without oxide removal. The coulombic efficiency of the oxide-removed NWs was higher than that of the pristine NWs (7.1% increase). The NWs were stable over 25 cycles at different C-rates. This approach provides an efficient and practical way to resolve the oxide issue of Ge-based anodes, and high-performance lithium-ion batteries were demonstrated using the oxide-removed NW anodes. This study presents an advance towards the realization of the commercial batteries based on Ge as an active electrode material.

Tuning the topographical parameters of Si pyramids for a better surface enhanced Raman response.

Development of facile routes for the fabrication of surface enhanced Raman substrates (SERS) along with optimal conditions for a high enhancement factor are significant from an application perspective of SERS. Despite steady efforts to establish high SERS signals, cost effectiveness without compromising the enhanced and robust Raman signal remains a major challenge. To address this aspect, herein, we try to tune the topographical aspects of Si pyramidal textures in pursuit of efficient SERS substrates. These pyramidal surfaces are deployed as a pre-template for adopting a SERS substrate using a cost-effective wet chemical etching method. By controlling the etching time, various topographical parameters namely base size, height, pyramidal number density and uniformity of pyramidal textures are modulated. To make all the surfaces SERS active, a Au (50%)-Ag (50%) alloy nanolayer is post-deposited over them. Furthermore, SERS behavior of all the surfaces is investigated by using Rh6G dye as an analyte molecule. In addition to the high density of hot spots in terms of pyramidal number density, base size and uniformity shows a strong correlation in deciding the substantial SERS response. Furthermore, we find a high enhancement factor (∼1.42 × 108) for the substrate consisting of dense, small and uniformly sized pyramids. Finite Difference Time Domain (FDTD) simulations done on similar structures corroborate our results. Additionally, universal applicability of the proposed substrate is also verified by detecting methylene blue and methyl parathion analyte molecules. These substrates are much cheaper (∼5 USD for 1 × 1 cm2) in comparison with commercially available Klarite SERS substrates (∼100 USD for 2 × 2 mm2). We believe this work provides a critical insight into the design of potential SERS substrates using a significantly cost-effective wet chemical etching process.

Morphological and Electrical Characterization of SiNWs Synthesized by Electroless Metal Assisted Chemical Etching Method

Morphological and Electrical Characterization of SiNWs Synthesized by Electroless Metal Assisted Chemical Etching Method

Evaluation of chemical composition, heat treatment, mechanical properties and electro chemical polishing for additively manufactured stent using ASTM F75 cobalt based superalloy (CoCrMo) by selective laser melting (SLM) technology.

ABSTRACT This paper evaluates and demonstrates the methods for additively manufactured stent and the use of material ASTM F75 Cobalt-based superalloy (CoCrMo) by evaluating the chemical content, hot isostatic pressing process, mechanical properties, and electrochemical polishing. The commercialise stent available had cause issues in the like of unmatch fitting in the blood vessel, with highly dependent on surgeon guessing during angioplasty; thus, the risk of restenosis or thrombosis can occur. By SLM technique, it creates complex products with high geometric accuracy while allowing the design freedom to produce patient-specific stent. The heat treatment for additively manufactured stent has been done through a series of Hot Isostatic Pressing (HIPing) cycle 1200°C and 14,150 PSI. The sample preparation by chemical etching method was delivered to assess the effect of as-built sample and HIPing where it showed the change pattern of the microstructure. The chemical composition has been assessed by Energy-Dispersive X-ray spectroscopy (EDX) and showed the presence of element Cobalt, Chromium, Molybdenum, and Carbon content. The compressive, flexural, and hardness testing has been conducted to determine the behaviour for an as-built sample and HIPing where the stiffness is drastically improved by 10%.

Molecularly imprinted electrochemical sensor for ascorbic acid determination based on MXene modified electrode

Molecularly imprinted electrochemical sensor for ascorbic acid (AA) detection was prepared based on MXene modified glassy carbon electrode (MIPs/MXene/GCE). MXene with layered structure was synthesized by chemical etching method and the o-phenylenediamine (o-PD) polymer was electrochemically polymerized onto MXene modified electrode surface. With the binding of AA molecules onto electrode, the current response of the sensor was decreased. Under the optimized experimental conditions, the current response change of the sensor was in linear with the concentration of AA in the range from 0.5 μM to 10 μM with detection limit of 0.27 μM. The sensor has good selectivity, which was applied to the determination of AA in vitamin C tablets.

Modeling and Recipe Optimization of Anti-Glare Process Using Sandblasting for Electronic Display Glass

Recently, anti-glare (AG) surface treatment technology has been considered as a standard process to enhance the visibility of electronic display devices. For AG, the hydrofluoric acid (HF)-based chemical etch method is the most common approach for the current display glass industry. However, in order to overcome the environmental and durability degradation problems of the HF-based chemical etch method, this paper proposes an eco-friendly physical surface treatment technology using the sandblasting method. Based on the preliminary analysis results using the central composite design (CCD) method-based response surface modeling methodology (RSM), additional experiments and analyses were performed for process modeling and optimal process recipe generation. To characterize the sandblasting process, the mean value of haze was considered as the process output, and the pressure of the nozzle, the distance of the nozzle from the surface of glass, the glass feed rate, and the grit size of the abrasives were considered as process inputs. Based on the process model using the statistical response surface regression method and machine learning-based approaches, the proposed method can generate optimized process recipes for various haze targets of 10%, 20%, and 30%, with an average haze difference of 0.84%, 0.02%, and 0.86%, and maximum deviations of 1.26%, 1.14%, and 1.4%, respectively. Through the successful completion of this work, it is expected that the proposed surface treatment method can be applied to various products including mobile phones, tablet PCs, and windshields of vehicles.

Growth and properties of manganese doped Ca3(VO4)2 single crystals

Calcium orthovanadate Ca3(VO4)2 crystals with the whitlockite structure as nominally pure as doped with manganese ions have been grown by the Czochralski method from melt in air in the [100] direction. The single crystals of optical-quality were obtained for 0.05–2 wt% Mn2O3 doping level in the melt. X-ray diffraction analysis was carried out. Analyze of the parameters of diffraction peaks indicates the microstructure improving for manganese doped crystals. The absorption spectrum of doped Ca3(VO4)2:Mn is characterized by a combination of absorption bands specific for Mn2+, Mn3+ and Mn5+ ions, it was also proved by spectroscopic measurements. Two fluorescence spectra were observed under 670 nm excitation: narrow fluorescence line peaking at about 1180 nm, which quite well fits the position of Mn5+ ions and broad band peaking at 1250 nm, which quite well fits the position of Mn3+ ions. Fluorescence in the visible range was observed in Ca3(VO4)2:Mn crystal. The specific domain structure of ferroelectric Ca3(VO4)2 crystal was revealed by the method of selective chemical etching depending on crystal composition and thermal treatment. The anisotropic character of the optical properties of the material was estimated.

The formation of SiNWs depending on the topology of the metal-catalyst film in the process of metal-assisted chemical etching of c-Si

The method of metal-assisted chemical etching for obtaining silicon nanowires, which consists of two stages, was studied. The conditions and modes for producing layers at both stages of the implemented technology are established, which include (1) chemical deposition of an array of self-organizing Ag nanoparticles on a Si substrate as a catalyst mask and (2) chemical etching of SiNWs to various depths from 110 to 1200 nm. The optical properties and morphology of a metal-catalyst (Ag) film were studied depending on the deposition time and solution concentration. Spectral ellipsometry was used to characterize the samples at all stages of MACE. Using the measured ellipsometric angles, the dielectric functions were determined, as well as the thicknesses and parameters of the fractions of composite layers in a multilayer model by approximating the effective Maxwell Garnett and Bruggeman medium for two-component layers. Samples with Ag nanoparticles with different morphologies were studied using reflection spectrophotometry in the wavelength range from 200 to 600 nm. The results showed that composite Ag-Si structures are promising for obtaining plasmon effects in both the visible and IR spectral regions.

Holey Reduced Graphene Oxide/Carbon Nanotube/LiMn0.7Fe0.3PO4 Composite Cathode for High-Performance Lithium Batteries

Introduction Graphene is a single atomic monolayer of graphite and has been found a variety of applications in energy conversion and storage devices, due to the excellent properties such as high carrier mobility (~10,000 cm2 V−1 s−1 at room temperature), structural flexibility, chemical and thermal stability, mechanical strength and ultrahigh theoretical specific surface area (2630 m2g−1) [1]. However, when the graphene sheet has large area, the wrapping of active materials may hinder the transportation of Li+ between active particles and electrolyte, especially at high charge/discharge rates.Herein, holey graphene oxide (h-GO) [2], which is made by a green wet ball-milling of GO in one step without using any catalysts or chemicals, is combined with carbon nanotubes (CNTs) and LiMn0.7Fe0.3PO4 (LMFP) to make a composite cathode for lithium batteries [3]. Results show that the LMFP cathode with h-GO/CNT shows a remarkedly improved electrochemical performances due to the facilitated Li+ transport pathway, compared to that with conventional GO/CNT. This study provides a new approach for fabricating holey graphene and can open up new possibilities for applications on power sources. Results and discussion The synthesis of h-GO and LMFP composite material is shown in Fig. 1. Graphite oxide suspension (~0.6 mg/mL) was obtained by mixing with purified water and after the ultrasonic treatment for 3 hours. Subsequently, the ball-milling of 50 mL GO suspension was performed in a planetary ball-mill machine with 30–120 g of 100 mm size zirconia balls for 20 min at 400 rpm (the corresponding weight ratio of balls to GO aqueous suspension is 0.6−2.4). The balls were fully removed by sieve afterward. Finally, the mixture was freeze-dried for 12 hours. LMFP, h-GO, CNTs and binder were mixed at a mass ratio of 95.6%: 2%: 0.4%: 2% and coated onto Al foil to obtain a cathode electrode. Electrochemical characteristics were evaluated by preparing a 2032 type coin cell using Li foil as the counter electrode. The electrolyte was 1 mol dm-3 LiPF6/EC-DEC (1: 2).SEM image of the synthesized h-GO is shown in Fig. 2. It is found that irregular micropores can be generated on the surface of GO after the ball-milling of GO aqueous suspension. At the conference, we will show that the more balls used, the more and bigger holes could be observed. That is, the hole size and surface density could be controlled by the adjustment of the weight ratio of balls to GO aqueous suspension. We will also show that LMFP electrode with h-GO/CNT can deliver more than half of discharge capacities than that with conventional GO/CNT at a higher discharge rate (>=20 C), also superior to that with h-GO or CNT only. The use of h-GO made by the other method, such as the chemical etching method, the performances will also be discussed. The scalable and robust synthesis method of h-GO and the novel properties of h-GO/CNT reported here greatly advance the practicality of using it as electrodes in lithium batteries as well as other energy storage technologies. Acknowledgment We thank Taiheiyo Cement Co., Ltd for the providing of LiMn0.7Fe0.3PO4 powders and NIMS for the TEM measurement. Reference 1. Han, et.al., Small. 9 (2013). 2. Y. Xu, et al., Nat. Commun. 5 (2014). 3. D. Ding, et.al., J. Power Sources. 449 (2020). Figure 1

Wet Texturing of a Multi-Crystalline Si-Wafer Using the Phenol-Formaldehyde Resin Mask

In the process of multi-crystalline silicon etched by the Metal Assisted Chemical Etching (MACE) method, due to its too small and uneven microstructures, heavy doping often occurs, which usually requires mixed acid (HNO3+HF) treatment, but this will ultimately affect the efficiency of crystalline silicon solar cells. In this article, phenol-formaldehyde (PF) resin, a main component of the positive photoresist, and water were dissolved in ethanol to form a PF resin-water-ethanol solution (PWEs) toward wet etching of multi-crystalline Si wafer, aim to prepared the texture structure with uniform distribution and reasonable size. A liquid film of PWEs was prepared on the Si wafer using dip-coating method. After the ethanol volatilizing, a mask of the resin was formed on the wafer through phase separation between the resin and water. A net like or a particle array mask was formed on the wafer through controlling the water/resin ratio, pulling speed and drying speed of the liquid film. With appropriate parameters above, a desirable particle array mask of PF resin was prepared. The size of particles and their spaces in this array were about $1{\mu }\text{m}$ and $2~{\mu }\text{m}$ respectively. With assistance of this particle array as a mask, a better textured surface of the Si wafer was prepared through MACE combined with etching of HNO3-HF mixed solution. The minimum reflectance of the wafer with the textured surface was as low as 14.2 %.

Scraps to superior anodes for Li-ion batteries: Sustainable and scalable upgrading of waste rust

The abundant iron rust of no value generated from industrial scraps presents environmental problem and burden. Chemical etching and related methods deployed to convert rust into α-Fe2O3 nanoparticles, however, have serious shortcomings namely higher chemical consumption and generation of secondary pollution. In an unprecedented illustration, herein the intercalation of ammonium bicarbonate (ABC) as a gaseous bubble template into bulky iron rust is described; formation of ammonium iron carbonate hydroxide hydrate and the reduction of particle size using a simple ball milling method followed by calcination is accomplished. The salient features of ABC, optimization of ratios (rust: ABC), and the ideal calcination temperature were optimized for attaining desirable properties of meso-α-Fe2O3 NPs. The electrode obtained at 500 °C delivered a superior reversible capacity of 1,055 mAh g−1 at 1 A g−1 over 100 cycles, which is comparable to the best performance reported for meso-α-Fe2O3 NPs. The superior electrochemical performance is ascribed to the porous nature of meso-α-Fe2O3 NPs maximizing the surface area, ensuring good charge transfer kinetics and enhanced pseudocapacitive contribution. Thus, we believe that the high-energy ball milling (HEBM) process represents a novel route for the scalable recycling of iron rust scraps for promoting the sustainable production of lithium-ion batteries.

Dual-Parameter Optical Fiber Probe Based on a Three-Beam Fabry-Perot Interferometer

Dual parameter detection without cross-sensitivity is a commonly important need but challenging, as most fiber detection components have a single sensitive mechanism. In this article, an optical fiber probe based on a three-beam Fabry-Perot interferometer (FPI) for temperature and refractive index (RI) measurement was proposed and experimentally realized. Theoretically, such structure has three reflective surfaces, forming three FPIs, and can obtain a hybrid sensing mechanism: wavelength-sensitive to temperature and intensity-sensitive to RI. Experimentally, the chemical etching method was used to form a concave in the fiber tip. Fused together with another section of un-etched fiber, an air bubble can be formed inside the fiber. Then, a cleavage near the bubble can shape the three-beam FPI. Using the fast Fourier Transform, the first-order spatial frequency is corresponding to the air-FPI, and the ratio of the second-order spatial frequency to first-order spatial frequency can describe how many smaller interference periods have been created within one original period due to the cleavage. The test temperature range is 30-40°C with a step of 2°C. The band pass filtering method was used to analyze different frequency components. Experimental results validate that the silica-FP was dominate for temperature sensing, and the average temperature sensitivity was 8.97 pm/°C with repeated linearity over 0.95. The test RI range was 1.3333-1.3908, and average RI sensitivity was 10.05 dB/RIU with repeated linearity over 0.92. Therefore, the proposed structure is a compact and efficient sensing component with hybrid sensitive mechanism that can achieve a temperature-RI dual-parameter measurement.