Challenges and Optimization of Building-Integrated Photovoltaics (BIPV) Windows: A Review

PV windows are seen as potential candidates for conventional windows. Improving the comprehensive performance of PV windows in terms of electrical, optical, and heat transfer has received increasing attention. This paper reviews the development of BIPV façade technologies and summarizes the related experimental and simulation studies. Based on the results of the literature research, the average comprehensive energy-saving rate of BIPV façades can reach 37.18%. Furthermore, limitations and optimization directions of photovoltaic integrated shading devices (PVSDs), photovoltaic double-skin façades, and photovoltaic windows are presented. To improve the energy-saving potential of windows as non-energy efficiency elements of buildings, smart PV windows are proposed to be the key to breakthrough comprehensive performance. However, not all switchable windows concepts can be applied to PV windows. Typical studies on smart windows and PV windows are sorted out to summarize the challenges and optimization of smart PV window technical solutions. Considering the technological innovations in smart PV windows, two requirements of energy-saving materials and building envelopes are put forward. The advances in materials and the building envelope are complementary, which will promote the sophistication and promotion of solar building technology

Wafer Surface Reconstruction Based on Shape From Focus

Scanning electron microscope, atomic force microscope and other equipment play an important role in the fields of topography restoration and detection. However, these devices are generally used in nanometer-scale measurement scenarios. For wafer topography quality control scenarios ranging from microns to hundreds of microns, these technologies have problems such as high cost and slow detection speed. Therefore, developing new, low-cost, and high-precision methods is necessary. To address this problem, a wafer surface reconstruction framework is proposed based on the shape-from-focus principle. In view of the characteristics of the large area and micro-small height of the wafer, to solve the limitations of the existing shape from focus framework, which is generally based on a single field, we created a multi-field image sequence rapid acquisition system and proposed the use of pulse control methods to achieve rapid acquisition of large area images. On the other hand, this paper proposes a dual filtering framework combining the Levy flight filtering principle with the SOR algorithm in point cloud filtering to achieve a balance between smoothing the depth map and maintaining the detailed structure, reducing the impact of noise, and improving the morphology restoration accuracy. To avoid splicing seams between fields, the progressive detection multifield stitching technique is used to complete large-area depth data stitching. Experiments were conducted on both synthetic and real objects to verify the effectiveness of the proposed method. In terms of synthesized images, the accuracy of the three methods significantly improved after applying the proposed method framework. After applying the Tenenbaum method framework, its correlation and peak signal-to-noise ratio improved by 7.5% and 38.2%, respectively, and its root mean square error was reduced by 40.7%. The excellent accuracy reconstruction results of the proposed method was verified through accuracy evaluation experiments. The height errors of the three methods used were all higher than $1~\mu \text{m}$ . However, after using the proposed method framework, the maximum error was only $0.24~\mu \text{m}$ . The experimental results indicated that this method overcomes the area limitation of traditional SFF and is suitable for applying wafer surface morphology measurements

Overview of the MEMS Pirani Sensors

Vacuum equipment has a wide range of applications, and vacuum monitoring in such equipment is necessary in order to meet practical applications. Pirani sensors work by using the effect of air density on the heat conduction of the gas to cause temperature changes in sensitive structures, thus detecting the pressure in the surrounding environment and thus vacuum monitoring. In past decades, MEMS Pirani sensors have received considerable attention and practical applications because of their advances in simple structures, long service life, wide measurement range and high sensitivity. This review systematically summarizes and compares different types of MEMS Pirani sensors. The configuration, material, mechanism, and performance of different types of MEMS Pirani sensors are discussed, including the ones based on thermistors, thermocouples, diodes and surface acoustic wave. Further, the development status of novel Pirani sensors based on functional materials such as nanoporous materials, carbon nanotubes and graphene are investigated, and the possible future development directions for MEMS Pirani sensors are discussed. This review is with the purpose to focus on a generalized knowledge of MEMS Pirani sensors, thus inspiring the investigations on their practical applications

Energy-Saving Potential Comparison of Different Photovoltaic Integrated Shading Devices (PVSDs) for Single-Story and Multi-Story Buildings

Building-integrated photovoltaic (BIPV) façades are a promising technique for improving building energy performance. This study develops energy simulation models of different photovoltaic-integrated shading devices (PVSDs) in single-story and multi-story office buildings. A cross-region study in China is carried out to explore the energy performance of PVSDs in five climate zones. The shading effect of the upper PVSDs is taken into account. The results show that (1) PVSDs can be applicable in hot and cold climates; shading effects lead to a notable difference in the optimal PVSDs style. The average comprehensive energy saving ratios of different PVSDs ranged from 16.12% (fixed PV louvres in the vertical plane) to 51.95% (lower single panel). The most rewarding PVSDs are for single-story buildings in Kunming and the least suitable are for multi-story buildings in Guangzhou. (2) In climate zones with little air-conditioning energy consumption, avoiding considerably increased lighting consumption by PVSDs is vital. (3) To reduce shading effects, solar panels with smaller widths or vertical placements can be adopted. In addition, the distance of the PV modules from the top edge of the windows is also critical. Building performance evaluation in the early design stage enables maximum benefits for the same input (total area of PV panels). The research methodology and data analysis presented can guide parameters design and the geographical applicability of PVSDs, providing a reference for optimal building energy performance

Overcoming photovoltage deficit via natural amino acid passivation for efficient perovskite solar cells and modules

Electronic defects at grain boundaries and surfaces of perovskite crystals impair the photovoltaic performance and stability of solar devices. In this work, we report the compensation of photovoltage losses in blade-coated methylammonium lead triiodide (MAPbI3) devices via passivation with natural amino acid (NAA) molecules. We found that the optoelectronic properties of NAA-passivated perovskite films and the corresponding device performances are closely correlated with the molecular interaction strength. A side-by-side comparative study of four typical NAAs reveals that arginine (Arg) functionalized with a guanidine end group exhibits optimum passivation effects owing to the strongest coordinative bonding with the uncoordinated Pb2+, which markedly suppresses the detrimental antisite PbI deep level defects. As a result, nonradiative charge recombination is significantly reduced, resulting in a substantially increased open-circuit voltage (VOC) of 1.17 V and a high efficiency of 20.49%. A solar module with an active area of 10.08 cm2 is also fabricated, yielding an efficiency of 15.65% with negligible VOC losses. In parallel, the Arg-passivated solar devices exhibit enhanced operational stability due to the formation of a hydrophilic Arg protective layer which encapsulates the perovskite crystals

Slot-die coating large-area formamidinium-cesium perovskite film for efficient and stable parallel solar module

Perovskite solar cells have emerged as one of the most promising thin-film photovoltaic (PV) technologies and have made a strong debut in the PV field. However, they still face difficulties with up-scaling to module-level devices and long-term stability issue. Here, we report the use of a room-temperature nonvolatile Lewis base additive, diphenyl sulfoxide(DPSO), in formamidinium-cesium (FACs) perovskite precursor solution to enhance the nucleation barrier and stabilize the wet precursor film for the scalable fabrication of uniform, large-area FACs perovskite films. With a parallel-interconnected module design, the resultant solar module realized a certified quasi-stabilized efficiency of 16.63% with an active area of 20.77 cm². The encapsulated modules maintained 97 and 95% of their initial efficiencies after 10,000 and 1187 hours under day/night cycling and 1-sun equivalent white-light light-emitting diode array illumination with maximum power point tracking at 50°C, respectively