Reflective Layer Research Articles

Mechanical and optical properties of amorphous silicon nitride-based films prepared by electron cyclotron resonance plasma-enhanced chemical vapor deposition

Silicon nitride (SiNx) based films have been recognized as essential dielectric films in the microelectronics and optoelectronics industry due to their desirable properties, such as high electrical insulation, excellent thermal stability, and compatibility with integrated circuit fabrication processes. They are also a potential candidate for fabricating wavelength-selective reflective coatings and surface passivation layers in building-integrated photovoltaics technologies. SiNx-based films are one of the popular choices for antireflective coatings in photovoltaics as well. Recently, SiNx and oxynitride (SiOyNx) based thin film optical filters have been explored to provide distinct color rendering to solar-charged electrical vehicles. Since solar cells have a lifespan of many years and the coating surfaces are substantial, it is essential to produce films with controlled optical and mechanical properties and maintain mechanical integrity against corrosion and wear. This study aims to design a deposition process and optimize minimal parameters for stable plasma conditions during multilayer deposition of SiNx and SiOyNx films using an electron cyclotron resonance plasma-enhanced chemical vapor deposition reactor with SiH4/N2/O2/Ar precursor mixtures at 120 °C. The primary goal was to investigate the influence of gas flow adjustments on the optical and mechanical properties, specifically targeting the refractive index and mechanical properties of the films. We measured the refractive index and the absorption of the films using variable angle spectroscopic ellipsometry. Then, we evaluated the mechanical residual stress ex situ using the wafer curvature measurement method. We have determined the elastic modulus and the hardness of the films using nanoindentation. The experimental results have shown a significant dependence of the optical and mechanical properties on the deposition parameters. To investigate the factors contributing to the intrinsic mechanical stress and to better understand SiNx film degradation mechanisms, we have studied the effect of postdeposition thermal cycling on the properties of the films. Several thermal-cycling experiments from room temperature to 400 °C were performed on different SiNx films, and the results showed an irreversible variation of the mechanical stress toward the tensile stresses caused by delamination of the films, while the refractive index remained unchanged.

Flexible Al2O3/polymethyl methacrylate composite nanofibers for high-performance sun shading and radiative cooling

Radiative cooling utilizes high solar reflectivity and high infrared emissivity to achieve temperature cooling down, which has attracted extensive research interest as a zero-energy consumption manner. However, the design of photonic structures and metamaterials for radiative cooling do not exploit commercialization prospects due to high production costs and structural complexity. Here we propose an economical and scalable electrospinning method for fabricating high-performance sun-shading and radiative cooling composite flexible film. The composite film is a non-woven fabric of nanofibers with polymethyl methacrylate (PMMA) and aluminum oxide (Al2O3) nanoparticles. The diameter of the nanofibers distributes in the range of 300–1200 nm and Al2O3 nanoparticles are wrapped in the nanofibers. The nanofibers strongly scatter sunlight to enable high solar reflectivity and back-reflection layer is no more necessary. Molecular vibrations of PMMA and phonon polarization resonance of Al2O3 nanoparticles synergistically result in high infrared emissivity. At a thickness of 0.30 mm and with an Al2O3 content of 8%, this material exhibits exceptional solar reflectance levels of approximately 95% between wavelengths of 1.1–2.5 µm. Additionally, it demonstrates an extremely low rate of solar absorption of approximately 5.5% between wavelengths of 0.3–1.1 µm, distinguishing itself as a highly effective solar selective surface even without the inclusion of a back-reflective layer. Furthermore, the material exhibits ultrahigh infrared emissivity levels of approximately 0.98 within atmospheric windows ranging from 8 to 13 µm. These remarkable characteristics position this material as a highly promising candidate for use in solar thermal energy conversion systems. As a result, the device shows a cooling performance that reaches a temperature decrease of up to 4.3 °C under 1000 W/m2 peak solar intensity and a decrease of 5.9 °C during nighttime. The composite film has enormous potential for use in vehicle shading and personal thermal management. Moreover, its mechanical properties allow for the flexibility needed to meet the demands of everyday use. Our work provides a straightforward and scalable method to manufacture products with exceptional sun shading and radiative cooling capabilities.

Colorful low-emissivity paints for space heating and cooling energy savings

Space heating and cooling consume ~13% of global energy every year. The development of advanced materials that promote energy savings in heating and cooling is gaining increasing attention. To thermally isolate the space of concern and minimize the heat exchange with the outside environment has been recognized as one effective solution. To this end, here, we develop a universal category of colorful low-emissivity paints to form bilayer coatings consisting of an infrared (IR)-reflective bottom layer and an IR-transparent top layer in colors. The colorful visual appearance ensures the aesthetical effect comparable to conventional paints. High mid-infrared reflectance (up to ~80%) is achieved, which is more than 10 times as conventional paints in the same colors, efficiently reducing both heat gain and loss from/to the outside environment. The high near-IR reflectance also benefits reducing solar heat gain in hot days. The advantageous features of these paints strike a balance between energy savings and penalties for heating and cooling throughout the year, providing a comprehensive year-round energy-saving solution adaptable to a wide variety of climatic zones. Taking a typical midrise apartment building as an example, the application of our colorful low-emissivity paints can realize positive heating, ventilation, and air conditioning energy saving, up to 27.24 MJ/m2/y (corresponding to the 7.4% saving ratio). Moreover, the versatility of the paint, along with its applicability to diverse surfaces of various shapes and materials, makes the paints extensively useful in a range of scenarios, including building envelopes, transportation, and storage.

Cooling colors below ambient temperature

The colors of objects originate from reflection of light in certain directions and absorption of undesired light, producing substantial heating. Extensive efforts are expended to cool colorful objects to reduce their energy consumption. However, a strategy to cool colorful objects below ambient temperature while fully preserving their excellent color properties with high saturation and large viewing fields remains a significant challenge. Inspired by Morpho butterflies, we report a robust configuration consisting of a multilayer, disordered structure, and total reflection layer to cool colorful objects to overcome this challenge. Numerical simulations and experimental measurements demonstrated that our configuration can cool a class of colorful objects not only to a temperature of approximately 2°C below ambient temperature, but also with ultrahigh saturation (100%) and a wide range of viewing angles (±60∘). These colorful cooling films have significant potential for energy sustainability in buildings, vehicles, facilities, and equipment.

Real-Scene Reflection Removal With RAW-RGB Image Pairs

Most brands of modern consumer digital cameras nowadays are able to provide RAW-RGB image pairs conveniently, even in the automatic mode. RAW images store pixel intensities linearly related to the radiance, which could be beneficial for the image reflection removal (IRR) task. However, existing IRR solutions, usually directly restoring the background in the non-linear RGB domain, severely overlook the valuable information conveyed by readily-available RAW images. Such a negligence may limit the performance of IRR methods on real-scene images. To mitigate this deficiency, we propose a Cascaded RAW and RGB Restoration Network (CR3Net) by leveraging both the RGB images and their paired RAW versions. Specifically, we firstly separate background and reflection layers in the linear RAW domain, and then restore the two layers in the non-linear RGB format by converting RAW features into the RGB domain. A novel RAW-to-RGB module (RRM) is devised to upsample these features and mimic pointwise mappings in the camera image signal processor (ISP). In addition, we collect the first real-world dataset that contains paired RAW and RGB images for IRR. Compared with state-of-the-art approaches, our method achieves a significant performance gain of about 2.07dB in PSNR, 0.028 in SSIM, and 0.0123 in LPIPS tested on the captured dataset. The source code and dataset are available at https://github.com/NamecantbeNULL/RAW_RGB_RR.

For 5G applications, high-gain patch antenna in Ka-Band

<span>The fifth generation (5G) of telecommunications is an attractive application for many researchers during the last years. The 5G requires high date rate with low latency communication medium and patch antenna was used recently for this application. In this article a patch antenna for 5G at 38 GHz was proposed. This article worked on enhancing the gain of patch antenna at Ka-Band and reducing side lobes level (SLL) in radiation pattern. The gain of the patch antenna was improved using a reflector layer located under antenna’s ground with free space air gap separating between two layers. Moreover, the SLL were reduced to satisfy low latency condition for 5G communications. The proposed antenna shows high gain around 8.10 dB with high front-to-back (F/B) ratio of 16.24 dB and wide operating bandwidth around 1.4 GHz for high data rate requirements as well as having reduced overall size antenna. The article based on analytical calculations for patch dimensions and optimization procedure to achieve the desired performance of antenna. Computer simulation technology (CST) had been used as an environment for simulation.</span>

Application of Carbon Nanosphere Templates for Preparation of Inverse Opal Photonic Crystals in Dye‐Sensitized Solar Cells

Carbon nanospheres are successfully synthesized with a particle size of about 140 nm using a two‐step hydrothermal method and used the carbon nanospheres as the deposition template material on the surface of P25(TiO2) by means of vertical deposition method. The antiopaline TiO2 photonic crystal (PC) structure is further prepared via immersed carbon nanospheres in TiO2 precursor solution, and the antiopal PC is used as the scattering layer of the photoanode of dye‐sensitized solar cell (DSSCs). As a comparison, the antiopal PC reflective layer is also prepared on the photoanode of DSSCs using polystyrene nanospheres as the template material. The photoanodes with those PC scattering layers prepared with different template materials are fabricated into complete DSSCs. The final photoelectric conversion efficiency of the DSSCs prepared with carbon nanospheres as the template material reaches 7.02%, which is comparable to the cells prepared with polystyrene nanospheres as the template material. The efficiency of the cell with the scattering layer is increased by about 16% compared with that of the normal DSSC based on P25.

Q-Compensated Gaussian Beam Migration under the Condition of Irregular Surface

The viscosity of actual underground media can cause amplitude attenuation and phase distortion of seismic waves. When seismic images are processed assuming elastic media, the imaging accuracy for the deep reflective layer is often reduced. If this attenuation effect is compensated, the imaging quality of the seismic data can be significantly improved. Q-compensated Gaussian beam migration (Q-GBM) is an effective seismic imaging method for viscous media, and it has the advantages of both wave equation and ray-based Q-compensated imaging methods. This study develops a Q-GBM method in visco-acoustic media with an irregular surface. Initially, the basic principles of Gaussian beam in visco-acoustic media are introduced. Then, by correcting the complex-value time of the Gaussian beam in visco-acoustic media, energy compensation and phase correction are carried out for the forward continuation wavefield at the seismic source of the irregular surface and the reverse continuation wavefield at the beam center, which effectively compensates the absorption and attenuation effects of visco-acoustic media on the seismic wavefield. Further, a Q-GBM method under the irregular surface is proposed using cross-correlation imaging conditions. Through migration tests for three numerical models of visco-acoustic media with irregular surfaces, it is verified that our method is an effective depth domain imaging technique for seismic data in visco-acoustic media under the condition of irregular surfaces.

Identification of interbedded gas hydrate and free gas using amplitude versus offset forward modelling

AbstractThe complex contacts between gas hydrate and free gas have been confirmed by gas hydrate pilot production in the Pearl River Mouth Basin, South China Sea. The laminated clay silt reservoirs have high amplitude reflections which may be filled with different saturations of gas hydrates, free gas and the coexistence between gas hydrate and free gas. To distinguish the variations of amplitude reflections caused by different reservoirs properties below the bottom simulating reflection, we combine the forward modelling, pre‐stack gathers with different incident angles and well log analysis to conduct the seismic responses. A number of geological models are established with variable saturations and different interfaces between gas hydrate and free gas. First, we analyse the seismic and well log responses at Sites W11, W01 and W17 near the production test area. Then, we perform the forward modelling to quantify the differences among seismic reflections with different saturations, thickness, incident angles and strata dips in free gas‐ or gas hydrate‐bearing geological models. We extract the seismic amplitudes along the bottom simulating reflection and other layers to compare with the amplitudes generated from forward modelling. The results indicate that the inclined intervals below the bottom simulating reflection have high amplitude, continuous reflection and polarity reversal which may be caused by thin gas reservoir and the interlayered gas hydrate and free gas with different saturations. The top interfaces of the gas hydrate‐ and free gas‐bearing layers show typical Class III amplitude versus offset and exhibit high amplitude reflections at seismic data with near, mid and far‐incident angles, which are easy to distinguish. Seismic response of far‐incident angle can be used to identify the coexistence of gas hydrate and free gas.

Optimization of SiO2 reflective layer thickness for improving the performance of structured CsI scintillation screen based on oxidized Si micropore array template in X-ray imaging.

Structured scintillation screen based on oxidized Si micropore array template can effectively improve the spatial resolution of X-ray imaging. The purpose of this study is to investigate the effect of SiO2 layer thickness on the light guide and X-ray imaging performance of CsI scintillation screen when the structural period is as small as microns. Cylindrical micropores with a period of 4.3 µm, an average diameter of 3.3 µm and a depth of about 40 µm were prepared in Si wafers. SiO2 layer was formed on the pore walls after thermal oxidation. Increasing SiO2 layer thickness would be beneficial to the propagation of scintillation light along the cylindrical channels. What was not previously anticipated was that the pore size gradually shrank as the SiO2 layer thickened. The pore shrinkage would reduce the filling rate of CsI in the templates and thus would reduce the production of scintillation light. The structured CsI scintillation screens with different SiO2 layer thicknesses were fabricated by filling CsI scintillator into the oxidized silicon micropore array template. The morphology, crystallinity, X-ray excited optical luminescence, and X-ray imaging performance of the screens were studied. The results show that the spatial resolutions of X-ray images measured using the structured CsI scintillation screens with different SiO2 layer thicknesses are close to each other, and they are all about 110 lp/mm. However, the X-ray excited optical luminescence of the screen and detective quantum efficiency of X-ray imaging vary with the thickness of the SiO2 layer. The optimal thickness is about 350 nm.

Exploring a radically new exponential Retinex model for multi-task environments

The Retinex Theory (RT) and its adaptations have gained significant popularity in the field of image processing. Nevertheless, traditional Retinex algorithms are generally customized to specific tasks. Besides, their use of logarithmic transformation (LT) to convert the multiplicative model to an additive one often results in the loss of texture information in the reflectance layer. In contrast to conventional methods, our approach involves direct decomposition of the observed image. This approach circumvents the necessity of intermediate transformations, thereby preserving essential texture features. In this study, we introduce a weight-aware ℓ1-ℓ2 technique based on the assumption that the reflectance layer is discontinuous and the illumination layer is spatially smooth. To preserve texture and structural information in the illumination layer, we introduce a weight-aware illumination component coefficient, ℓ1-norm, and estimate the reflectance component using ℓ2-norm. By utilizing weight-aware coefficients, the proposed technique is highly effective in addressing the issue of texture loss in the reflectance layer. Additionally, we employ ℓ2-norm to extract accurate information from the reflectance layer and implement a bright channel prior to prevent ambiguity during the decomposition process. We utilize an alternating minimization approach to obtain the optimal objective function solution and modify the illumination layer using gamma and non-linear stretching algorithms. Our proposed technique not only tackles the problem of texture duplication but also improves the quality of low-light images, and can be seamlessly integrated with various image and vision-based tasks. Our evaluation of eight benchmark datasets using 15 quality metrics, along with a variety of 22 conventional and modern algorithms, shows that the proposed algorithm is capable of delivering competitive qualitative and quantitative results without compromising its flexibility and scalability. Besides, the proposed model is evaluated on retinal images, and the results demonstrate a substantial improvement in the accuracy of learning-based models.

Gradient Hierarchical Hollow Heterostructures of Ti3C2Tx@rGO@MoS2 for Efficient Microwave Absorption.

Heterostructure engineering has emerged as a promising approach for creating high-performance microwave absorption materials in various applications such as advanced communications, portable devices, and military fields. However, achieving strong electromagnetic wave attenuation, good impedance matching, and low density in a single heterostructure remains a significant challenge. Herein, a unique structural design strategy that employs a hollow structure coupled with gradient hierarchical heterostructures to achieve high-performance microwave absorption is proposed. MoS2 nanosheets are uniformly grown onto the double-layered Ti3C2Tx MXene@rGO hollow microspheres through self-assembly and sacrificial template techniques. Notably, the gradient hierarchical heterostructures, comprising a MoS2 impedance matching layer, a reduced graphene oxide (rGO) lossy layer, and a Ti3C2Tx MXene reflective layer, have demonstrated significant improvements in impedance matching and attenuation capabilities. Additionally, the incorporation of a hollow structure can further improve microwave absorption while reducing the overall composite density. The distinctive gradient hollow heterostructures enable Ti3C2Tx@rGO@MoS2 hollow microspheres with exceptional microwave absorption properties. The reflection loss value reaches as strong as -54.2 dB at a thin thickness of 1.8 mm, and the effective absorption bandwidth covers the whole Ku-band, up to 6.04 GHz. This work provides an exquisite perspective on heterostructure engineering design for developing next-generation microwave absorbers.

Estimating Reflectance Layer from a Single Image: Integrating Reflectance Guidance and Shadow/Specular Aware Learning

Estimating the reflectance layer from a single image is a challenging task. It becomes more challenging when the input image contains shadows or specular highlights, which often render an inaccurate estimate of the reflectance layer. Therefore, we propose a two-stage learning method, including reflectance guidance and a Shadow/Specular-Aware (S-Aware) network to tackle the problem. In the first stage, an initial reflectance layer free from shadows and specularities is obtained with the constraint of novel losses that are guided by prior-based shadow-free and specular-free images. To further enforce the reflectance layer to be independent of shadows and specularities in the second-stage refinement, we introduce an S-Aware network that distinguishes the reflectance image from the input image. Our network employs a classifier to categorize shadow/shadow-free, specular/specular-free classes, enabling the activation features to function as attention maps that focus on shadow/specular regions. Our quantitative and qualitative evaluations show that our method outperforms the state-of-the-art methods in the reflectance layer estimation that is free from shadows and specularities.

Study on ablation behavior and mechanism of C/SiC composite irradiated by a laser with various parameters

AbstractC/SiC composite has been widely used as a high‐temperature material for engineering components due to its excellent thermal properties. Facing the rapid development and threat of high‐energy laser, study on the ablation resistance under laser irradiation is strongly required. In this work, a continuous high‐energy laser was applied to explore the laser ablation behavior and mechanism of C/SiC composite. From the results, C/SiC composite shows different morphologies when irradiated at various laser power densities for 500 and 700 W/cm2. We divided the ablation area into three regions; the central, transition, and edge regions, where the formation of SiO2, SiO, and the breakage of carbon fiber were observed. The generated highly reflective SiO2 layer reduces the absorption of laser energy, which is beneficial to lower the back‐surface temperature and reduce the damage of composite. In addition, we put forward the ablation physical models and ablation mechanisms irradiated at different power densities. The work provides a basis for the laser ablation resistance of C/SiC composites under different conditions.

REVOLUTIONIZING PHOTOGRAMMETRY: USING MIRRORS IN SINGLE-IMAGE PHOTOGRAMMETRY

Abstract. The present work introduces a new low-cost prototype® designed for photogrammetric surveys of small objects, using a single photographic shot. The prototype® utilizes the different perspectives of the object presented by a series of mirrors strategically placed in the camera sensor. The set of specular reflections projected on our camera sensor simulates the same effect as taking pictures from equivalent points of each mirror.The v1 prototype® was presented at the 7th International Workshop "Low-Cost 3D Sensors, Algorithms, Applications" in Würzburg on December 15–16, 2022. It consists of a set of eighteen common mirrors conveniently placed around the object to be digitized, making its reflections converge towards the camera lens. The v2 prototype® presented here is an evolution of the previous one, which replaces the common mirrors with precision ones that have a metallic reflective surface on the front. This modification eliminates the double image formed by the reflective layer and the protective glass.These prototypes® allow for faster surveys of small inert objects (such as small cultural heritage artefacts like sculptures, engravings, rings, coins, etc.) as well as photogrammetric surveys of small living beings, such as insects, which cannot remain still during traditional photography.

Detection of Bright Band Heights from Vertical Profile of Radar Reflectivity in Akure, South Western Nigeria

Bright band is an important phenomenon that occurs in radar observations of precipitation. It is a layer of intense reflectivity caused by the melting of the snowflakes in the atmosphere. Accurate detection of bright band and its associated properties are essential for the estimation of precipitation rates and characterization of precipitation types as required in Agriculture, Aviation, Navigation, Telecommunication sectors etc. Bright Band Height (BBH) is a vital parameter in the determination of rain height, rain-induced radio signal attenuation and mitigation techniques. This paper presents an empirical study on the measurement of BBH and Zero Degree Isotherm Height (ZDIH) from Micro Rain Radar (MRR) data obtained in Akure, Nigeria. Vertical profile of radar obtained during stratiform rainy events were examined to detect bright bands and its features. Analysis of the result showed that the ZDIH varies between 4.48 and 4.60 km while the BBH also vary from 4.16 to 4.48 km during intense rainy events in September and October 2010. The derived propagation data would be needed for the optimization and improvement of quality of service (QoS) offered by earth-space links during rainy events in Akure and its environs.

The Role of Management Science in Forming Next Era Semantics

AbstractThe author has previously in a social system theoretical perspective outlined a position for engaged scholarship in bridging the gulf between theorizing and practice. Partaking as “midwives” for shared semantics in a polycentric network was analyzed as one role for engaged scholars to assist. This paper, however, argues that for a shared semantic reservoir for “next era” leadership and management to form, one more layer of reflection is needed: how to manage “backwards” from the future. The paper also addresses geographic inclusion/exclusion, which seems to be reinforced as digitalization and abstract knowledge are gaining ground, even though bits and abstract knowledge should easily be detached from spatial limitations. Research programs targeting “grand challenges” and “grand solutions” is defined by megaprojects defined and financed by large foundations or other large-scale actors, and well-connected international research centers and research networks are needed to influence this agenda-setting. The paper argues that forming regional polycentric networks (including scientific research scholars) may to a greater extend bridge the global agendas with local and regional issues to not be excluded in a transition process.

Dual-Band Terahertz Metamaterial Absorber and Its Refractive-Index-Sensing Application for Material Films

Metamaterial absorbers are an emerging and rapidly growing technology with potential applications in optoelectronics, such as refractive index sensing and energy harvesting. Herein, a dual-band terahertz metamaterial absorber is investigated by exploiting a patch of circular loops and cross-shaped structures. The designed absorber composes of a periodic metallic metasurface and a continuous reflector layer, which are separated by a benzocyclobutene dielectric film. The perfect absorptivity properties of the absorber, revealed at frequencies of 0.6 and 1.2 THz, can be flexibly designed by manipulating the geometrical dimensions. A sample of the designed absorber prototype is manufactured under a microfabrication process and measured through a terahertz time-domain spectrometer in free space. In addition, the potential application of the proposed terahertz absorber in refractive index sensing is analyzed and experimentally verified, which has an excellent unit sensitivity of 0.13 THz/RIU at 0.6 THz and 0.27 THz/RIU at 1.2 THz, respectively. The practicability in sensing applications is verified by coating polyimide and poly(dimethylsiloxane) dielectric films on the surface of the absorber, and the absorption frequency shifts at 1.2 THz are practically coincident with the simulated ones. This proposed prototype is an effective manner for terahertz metamaterial absorbers with potential applications in the sensor field.

Thermal neutron reference radiation facility with high thermalization and large uniformity area

A new thermal neutron facility based on 12 241Am–Be neutron sources has been established at the National Institute of Metrology, China. It has two independent irradiation fields, the inner field and outer field, constructed with high-purity graphite and heavy water as moderators, respectively. Three innovative designs, including the reflection cavity, reflection layer, and homogenizing lens, were introduced to improve the performance of the facility. The reflection layer can increase the thermal neutron fluence rate by about 3–4 times, the reflection cavity also enhances thermal fluence by 3–4 times by taking advantage of multiple scattering of neutrons, and the homogenizing lens mounted on the neutron exit surface of the moderator improve the distribution of thermal neutron. The characteristics of the two fields were investigated by Monte Carlo simulations and experimental measurements. The results show that the new facility has high thermalization and large uniformity area with these innovative designs. For the inner field, the thermal neutron fluence rate at the reference position is (21 433.3 ± 407.2) cm−2 s−1, the cadmium ratio is 20.6, the non-uniformity is 0.1% over the 40 cm × 40 cm region. For the outer field, the thermal fluence rate at the reference position is (2046.0 ± 49.1) cm−2 s−1, the cadmium ratio is 1433, and the non-uniformity is 0.7% in the 70 cm × 70 cm region. The facility is expected to be suitable for the large-size detector, and its excellent performance is attractive for various thermal neutron experiments.

Factors influence analysis and life cycle assessment of innovative bifacial photovoltaic applied on building facade

Bifacial PV (BPV) could use both radiation on the front and back for power generation. The challenge is that reflected radiation absorbed by the back is limited when BPV is applied on building. BPV cannot be effectively utilized. In this research, BPV was innovatively combined with reflective film to form BPV curtain wall system, which is conducive to higher power output and could be applied to the facade of building directly. Compared with mono-facial PV, power generation of the system could be increased by 24% on average. Life cycle assessment (LCA) was used to analyze the influence of multi-factors on this system, which makes the evaluation of the performance more comprehensive. It could be found that the energy and greenhouse gas payback time could reach the shortest when the system is faced South. The results of the system become better with the increase of photovoltaic coverage, but this trend will gradually slow down when the coverage is greater than 75%. Besides, when the distance with reflective layer is about 1/12 L, the system has the shortest payback time. This research explored a new form of BPV system, and has beneficial effect on the field of application of BPV in buildings.