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Tin-based perovskite solar cells are expected to replace lead-based perovskite solar cells to achieve environmentally friendly devices. Currently, a significant challenge lies in low filling factor and short-circuit current density, leading to an overall lower efficiency of these cells. In this context, we conducted a comprehensive comparative study on the deposition of these three inorganic small-molecule materials (CsBr, CsCl, CsI) on tin-based perovskite layers. The results showed that depositing these three inorganic small-molecule materials (CsBr, CsCl, CsI) on tin-based perovskite layers can improve the topography of the thin film and display an increased grain size. Simultaneously, the presence of the passivation layer facilitates preferred crystal orientation and enhanced charge carrier transport capabilities. Furthermore, devices with passivation layers exhibit reduced series resistance and increased shunt resistance, leading to a higher filling factor, a higher short-circuit current density, and a reduced leakage current in the passivated devices. This results in an elevated overall conversion efficiency of the devices. Notably, among the three halide materials employed for passivation, CsI demonstrates the most effective passivation, with the champion device achieving an efficiency of 6.0%. This study contributes valuable insights into the passivation strategies for tin-based perovskite solar cells. [ABSTRACT FROM AUTHOR]

Metal halide perovskites have attracted considerable attention as novel optoelectronic materials for their excellent optical and electrical properties. Inorganic perovskites (CsPbX3, X = Cl, Br, I) are now viable alternative candidates for third-generation photovoltaic technology because of their high photoelectric conversion efficiency, high carrier mobility, good defect tolerance, simple preparation method and many other advantages. However, the toxicity of lead is problematic for practical implementation. Thus, the fabrication of lead-free perovskite materials and devices has been actively conducted. In this work, the energy band and photoelectric properties of inorganic perovskites CsBX3 (B = Pb, Sn, Ge, X = Cl, Br, I) have been investigated with the first principles calculation, and the possible defect energy levels and their formation energies in different components, in particular, have been systematically studied. The advantages and disadvantages of Sn and Ge as replacement elements for Pb have been demonstrated from the perspective of defects. This study provides an important basis for the study of the properties and applications of lead-free perovskites. [ABSTRACT FROM AUTHOR]

The power conversion efficiency of modern perovskite solar cells has surpassed that of commercial photovoltaic technology, showing great potential for commercial applications. However, the current high-performance perovskite solar cells all contain toxic lead elements, blocking their progress toward industrialization. Lead-free tin-based perovskite solar cells have attracted tremendous research interest, and more than 14% power conversion efficiency has been achieved. In tin-based perovskite, Sn2+ is easily oxidized to Sn4+ in air. During this process, two additional electrons are introduced to form a heavy p-type doping perovskite layer, necessitating the production of hole transport materials different from that of lead-based perovskite devices or organic solar cells. In this review, for the first time, we summarize the hole transport materials used in the development of tin-based perovskite solar cells, describe the impact of different hole transport materials on the performance of tin-based perovskite solar cell devices, and summarize the recent progress of hole transport materials. Lastly, the development direction of lead-free tin-based perovskite devices in terms of hole transport materials is discussed based on their current development status. This comprehensive review contributes to the development of efficient, stable, and environmentally friendly tin-based perovskite devices and provides guidance for the hole transport layer material design. [ABSTRACT FROM AUTHOR]

In recent years, lead halide perovskite materials have attracted great interest and are widely used in solar cells and light-emitting devices due to their high photoelectronic quantum yield, high color purity, high defect tolerance, long diffusion length, high carrier mobility, and bandgap tunability. However, the application of lead halide perovskites is limited due to the presence of Pb, making lead-free perovskites an important substitute due to their same crystal structure and similar properties. Although some reports have been made on lead-free perovskite materials, there are still great challenges to realize their application due to their poor stability, easy phase transition, and low photoelectric conversion efficiency. Here, we mainly summarize the development and application of ABX3-type lead-free halide perovskite materials, especially in optoelectronic devices. The article first introduces the lattice and energy band structure, the optoelectronic properties of lead-free perovskites, including the research method of lead-free perovskites, and then analyzes the reasons for the low luminous efficiency and poor stability of lead-free perovskite materials. Second, the development history and current situation of lead-free perovskites in different optoelectronic device applications are summarized. Finally, we present the challenges and prospects for the future development of lead-free perovskites. [ABSTRACT FROM AUTHOR]

The rapidly developing organic–inorganic hybrid chalcogenide solar cells have now become a hot topic of interest. However, the bandgap of inorganic ferroelectric materials with a typical chalcogenide structure is too wide to match the solar spectrum, while the ferroelectricity of organic-inorganic hybrid chalcogenide materials with a narrow bandgap, meth amide–lead–iodine, is not obvious, and the lead element causes environmental pollution. The recently discovered organic–inorganic hybrid material [C6N2H18]BiI5 with good ferroelectricity and the narrowest bandgap of molecular ferroelectrics can absorb visible light in the range of 380 nm to 660 nm, and compound [C6N2H18]SbI5 with the Bi cognate element Sb was also synthesized. In this paper, we designed the first experiment to prepare thin films by mixing and doping the above two materials in five different molar ratios, and we comparatively studied the changes in crystal structure, surface morphology, and photophysical properties of the prepared multicomponent hybrid films according to the mixing ratio. A theoretical model was developed to calculate and analyze the bandgap of the hybrid doped compounds and compare it with the experimental values. It was found that the absorption spectra of the multicomponent hybrid films were red-shifted relative to the original material, indicating that the forbidden bandwidth was reduced to absorb a wider range of visible light, and the reason for this was thought to be the narrowing of the bandgap due to doping. When the mixing ratio was 0.4:0.6, the bandgap was the narrowest and the light absorption was the best; the highest quality of the film was obtained when the mixing ratio was 0.5:0.5. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Background Method Results and Conclusion Implications Drawing on family communication patterns theory, introducing psychological capital and liking of school, this study explores the effect of family communication patterns on university student networking behavior.Individuals can establish, maintain, and develop social networks through a series of proactive networking behaviors, effectively leveraging their position within these social networks. In terms of resource acquisition, the utility of networking behaviors is not inferior to an individual's social network position. Therefore, networking behaviors have received extensive attention from scholars, but research on networking behaviors of college students on campus is limited.Multiwave data were collected from 191 Chinese university students. Path analysis and bootstrapping methods were used to analyze data.We found that conversation orientation positively related to psychological capital. Psychological capital is positively related to networking behavior and mediates the effect of conversation orientation on networking behavior. Furthermore, liking of school moderates the effect of psychological capital on networking behavior and the indirect effect of conversation orientation on networking behavior through psychological capital, whereby the two effects are stronger when liking of school is high.The conclusion expands the research on family communication patterns and networking behavior on campus and provides practical enlightenment for parents and universities to improve college students' networking behavior on campus. [ABSTRACT FROM AUTHOR]