The power conversion efficiency (PCE) of perovskite solar cells (PSCs) has seen effective performance upgrades, showing remarkable academic research and commercial application value. Compared with commercial silicon cells, the PCE gap is narrowing. However, the stability, cost, and large-scale production are still far behind. For scale-up preparing high-efficiency and stable PSCs, there is a variety of related research from each functional layer of perovskite solar cells. This review systematically summarizes the recent research on the functional layers, including the electron transport layer, perovskite layer, hole transport layer, and electrode. The common ETL materials, such as TiO₂, SnO₂, and ZnO, need doping and a bi-layer ETL to promote their property. Large-scale and low-cost production of perovskite layers with excellent performance and stability has always been the focus. The expensive and instability problems of Spiro-OMeTAD and electrode materials remain to be solved. The main problems and future development direction of them are also discussed.

2D WS₂ is a promising candidate for the next generation nanoelectronics, spintronics, valleytronics, and optoelectronics. However, the uncontrollably large-area growth of WS₂ nanosheets and their unsatisfactory performance of the photodetectors based on WS₂ hindered its applications. Here, we proposed a CVD method using tungstic acid as the precursors to grow WS₂ flakes. After being characterized by AFM, Raman, PL, and TEM, we found the as-grown WS₂ flakes were high-quality structures. Then the photodetectors based on the as-grown WS₂ were fabricated, which exhibited high responsivity (7.3 A W⁻¹), a fast response rate (a response time of 5 ms and a recovery time of 7 ms), prefect external quantum efficiency (EQE) (1814%), and remarkable detectivity (D*) (3.4 × 10¹² Jones). Our works provided a new CVD method to grow some high-quality WS₂ nanosheets.

We have performed electrochemical treatment of the van der Waals antiferromagnetic materials ${\mathrm{FePS}}_3$ and ${\mathrm{NiPS}}_3$ with the ionic liquid $\mathrm{EMIM}\text{−}{\mathrm{BF}}_4$, achieving significant molecular intercalation. Mass analysis of the intercalated compounds, ${\mathrm{EMIM}}_x\text{−}{\mathrm{FePS}}_3$ and ${\mathrm{EMIM}}_x\text{−}{\mathrm{NiPS}}_3$, indicated respective intercalation levels, $x$, of approximately 27% and 37%, and x-ray diffraction measurements demonstrated a massive (over 50%) enhancement of the $c$-axis lattice parameters. To investigate the consequences of these changes for the magnetic properties, we performed magnetic susceptibility and ${}^{31}\mathrm{P}$ nuclear magnetic resonance (NMR) studies of both systems. For ${\mathrm{EMIM}}_x\text{−}{\mathrm{FePS}}_3$, intercalation reduces the magnetic ordering temperature from $T_N=120$ to 78 K, and we find a spin gap in the antiferromagnetic phase that drops from 45 to 30 K. For ${\mathrm{EMIM}}_x\text{−}{\mathrm{NiPS}}_3$, the ordering temperature is almost unaffected (changing from 148 to 145 K), but a change towards nearly isotropic spin fluctuations suggests an alteration of the magnetic Hamiltonian. Such relatively modest changes, given that the huge extension of the $c$ axes is expected to cause a very strong suppression any interlayer interactions, point to the conclusion that the magnetic properties of both parent compounds are determined almost exclusively by two-dimensional (2D), intralayer physics. The changes in transition temperatures and low-temperature spin dynamics in both compounds therefore indicate that intercalation also results in a significant modulation of the intralayer magnetic interactions, which we propose is due to charge doping and localization on the P sites. Our study offers chemical intercalation with ionic liquids as an effective method to control not only the interlayer but also the intralayer interactions in quasi-2D magnetic materials.

Large-area SnS ₂ nanosheets were grown through a CVD method by using SnCl ₂ on SiO ₂ /Si substrates as the precursors. The SnS ₂ nanosheets-based photodetectors shown high-performance.

All-inorganic CsPbX₃ perovskite material not only has the benefits of advanced light absorption coefficient, long carrier lifetime, and simple preparation process of organic–inorganic perovskite materials but it also maintains excellent stability under the erosion of damp heat. Stability is the premise of its industrialization, so all-inorganic perovskite is undoubtedly a very competitive direction for the development of perovskite materials. However, there are still many defects in the all-inorganic perovskite thin films, and it is difficult to obtain high power conversion efficiency (PCE). This review systematically summarizes additive engineering, solvent engineering, and interface engineering methods to promote the thin film property for a high PCE in recent years.

A layered Ti₃C₂T_x MXene structure was prepared by etching MAX-phase Ti₃AlC₂ with hydro-fluoric acid (HF), followed by alkalization in sodium hydroxide (NaOH) solutions of varying concentrations and for varying durations. Compared to sensors utilizing unalkalized Ti₃C₂T_x, those employing alkalized Ti₃C₂T_x MXene exhibited enhanced sensitivity for NH₃ detection at room temperature and a relative humidity of 40%. Both the concentration of NaOH and duration of alkalization significantly influenced sensor performance. Among the tested conditions, Ti₃C₂T_x MXene alkalized with a 5 M NaOH solution for 12 h exhibited optimal performance, with high response values of 100.3% and a rapid response/recovery time of 73 s and 38 s, respectively. The improved sensitivity of NH₃ detection can be attributed to the heightened NH₃ adsorption capability of oxygen-rich terminals obtained through the alkalization treatment. This is consistent with the observed increase in the ratio of oxygen to fluorine atoms on the surface terminations of the alkalization-treated Ti₃C₂T_x. These findings suggest that the gas-sensing characteristics of Ti₃C₂T_x MXene can be finely tuned and optimized through a carefully tailored alkalization process, offering a viable approach to realizing high-performance Ti₃C₂T_x MXene gas sensors, particularly for NH₃ sensing applications.