Shanghai Advanced Research Institute makes progress in the research of crystalline silicon solar cells
The cost reduction and efficiency increase of crystalline silicon (c-Si) solar cells is an important driving force for the development and popularization of photovoltaic power generation and achieving the goal of "carbon peak and carbon neutrality". Passivation contact solar cells represented by amorphous silicon/crystalline silicon heterojunction (SHJ) have achieved high conversion efficiency and have received extensive attention from the industry; SHJ cells have high parasitic light absorption, high equipment and process costs, etc. The problem prompted the academic community to look for alternative materials and processes. Recently, Li Dongdong, a researcher at the Shanghai Institute for Advanced Study of the Chinese Academy of Sciences, Lu Linfeng, an associate researcher, and others published a research result entitled Interfacial Engineering of Cu2O Passivating Contact for Efficient Crystalline Silicon Solar Cells with an Al2O3 Passivation Layer on ACS Applied Materials & Interfaces. Crystalline silicon and p-type Cu2O materials have low valence band deviation and high conduction band deviation. Therefore, the c-Si/Cu2O heterojunction can block electrons and realize the selective transmission of holes. In this study, the researchers used p-Si/Cu2O passivation contact heterojunction solar cells as the research object, and found that direct p-Si/Cu2O contact would result in a spontaneous formation of a substoichiometric SiOX interlayer. At the same time, the Cu element also diffuses to the silicon surface to form deep-level doping, reducing the minority carrier lifetime. The researchers then introduced an ultra-thin Al2O3 layer (~1 nm) on the p-Si/Cu2O interface, which not only acts as a passivation tunnel layer, but also inhibits the redox reaction and Cu diffusion at the Si/Cu2O interface . Combining the high work function of gold and the excellent optical properties of silver, the power conversion efficiency of solar cells based on p-Si/Al2O3/Cu2O/Au/Ag passivation contacts can reach 19.71%, which is the highest level reported for the same type of battery. This study reveals the interface characteristics and carrier transport mechanism of p-Si/Cu2O passivation contacts, and provides an effective strategy for reducing its interface defects and achieving selective carrier transport. It can be used as a universal method in It has been applied to improve the efficiency and stability of heterojunction cells, and provides new ideas for the research of other types of thin-film solar cells. The research work is supported by the National Natural Science Foundation of China, the Shanghai Municipal Science and Technology Commission and the Youth Innovation Promotion Association of the Chinese Academy of Sciences. Figure 1. Cu2O and Al2O3/Cu2O laminated films deposited on p-type Si wafers (a) the relationship between minority carrier lifetime and implantation concentration, and (b) saturation current density (J0S) Figure 2. XPS spectra of Cu 2p, Cu LMM, Si 2p and O 1s prepared on Cu2O films on p-Si and p-Si/Al2O3 substrates Figure 3. High-resolution transmission electron micrographs of the cross-section of Cu2O films prepared on p-Si and p-Si/Al2O3 substrates and the corresponding energy spectrum analysis Figure 4. (a) Schematic diagram of p-Si/Al2O3/Cu2O back contact heterogeneous cell, and (b) current density-voltage (JV) and (c) external quantum efficiency (EQE) curves of different stacked devices. (D) Under different metal back electrodes, the light absorption characteristics of bulk silicon and electrodes The Pm2.5 Mesh Screen is a revolutionary technology designed to filter out PM2.5 particles from the air, improving air quality and protecting human health. This innovative solution consists of a fine mesh that effectively captures and traps PM2.5 particles while allowing clean air to pass through. With its versatile applications in residential, commercial, industrial, and public settings, the Pm2.5 Mesh Screen offers a cost-effective and energy-efficient solution to combat air pollution. By understanding its significance, we can appreciate its potential to create a cleaner and healthier environment for all. PM2.5,Mesh screen,Air pollution Jinwu Glass Fiber Co., Ltd , https://www.jinwuwindows.com
