All-inorganic perovskite solar cells suffer from low performance due to unsatisfactory carrier transport and light harvesting efficiency. Semiconductor nanopillar arrays can reduce light reflection loss and suppress exciton recombination dynamics in optoelectronic devices. In all-inorganic perovskite solar cells, few studies employing TiO₂ nanopillar arrays (TiO₂ NaPAs) have been reported to improve the device performance. Herein, well-arranged TiO₂ NaPAs are chosen to enhance the interfacial contact between perovskite and electron transporting layers for improving the carrier transport. Notably, TiO₂ NaPAs can be directly fabricated on rigid/flexible substrates at roughly room temperature by unique glancing angle deposition, which is more available than high-temperature hydrothermal/solvothermal methods. By embedding TiO₂ NaPAs into chemical processable CsPbI₂Br layers, continuous and intimate films are readily formed, guaranteeing large physical contact for facilitating more effective electron injection and charge separation. The vertically grown TiO₂ NaPAs also provide a straightforward electron transporting path to electrodes. In addition, TiO₂ NaPAs can guide the incident light and enhance the light-harvesting ability of CsPbI₂Br films. As a result, the solar cell with TiO₂ NaPAs displays a power conversion efficiency of 11.35% higher than planar control of 10.04%, and exhibits better long-term thermal stability. This strategy provides an opportunity by constructing direct interfacial regulation towards the performance improvement of inorganic perovskite solar cells.

Hybrid silicon/organic solar cells have been recently extensively investigated due to their simple structure and low-cost fabrication process. However, the efficiency of the solar cells is greatly limited by the barrier height as well as the carrier recombination at the silicon/organic interface. In this work, hydrochloroplatinic acid (H2PtCl6) is employed into the poly(3,4-ethlenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) solution, and the work function (WF) of the PEDOT:PSS layer has been successfully improved. Based on the Pt-modified PEDOT:PSS layer, the efficiency of the silicon/PEDOT:PSS cell can be increased to 11.46%, corresponding to ~20% enhancement to the one without platinum (Pt) modification. Theoretical and experimental results show that, when increasing the WF of the PEDO:PSS layer, the barrier height between the silicon/PEDOT:PSS interface can be effectively enhanced. Meanwhile, the carrier recombination at the interface is significantly reduced. These results can contribute to better understanding of the interfacial mechanism of silicon/PEDOT:PSS interface, and further improving the device performance of silicon/organic solar cells.

Due to the good photocatalytic activity, the TiO2@CNTs thin film is highly desirable to apply to the self-cleaning glass for green intelligent building. Here, the TiO2@CNTs thin film has been successfully achieved by polymer-assisted approach of an aqueous chemical solution method. The polymer, polyethylenimine, aims to combine the Ti4+ with CNTs for film formation of TiO2@CNTs. The resultant thin film was uniform, highly transparent, and super-hydrophilic. Owing to fast electron transport and effectively hindering electron-hole recombination, the TiO2@CNTs thin film has nearly twofold photocatalytic performance than pure TiO2. The TiO2@CNTs thin films show a good application for self-cleaning glasses.

A novel crown ether lithium salt complex [Li∈12-C-4][I] has been designed, synthesized and characterized. The thermal properties of the [Li∈12-C-4][I] based solid-state electrolytes were also investigated in detail. The particular trapping ability of 12-crown-4 to Li⁺ can obviously reduce the cation–anion (Li⁺–I⁻) interaction and hence facilitate favorable electrical properties of the solid-state electrolytes. Therefore, [Li∈12-C-4][I] represents ionic conductivity of 3.93 × 10⁻⁵ and 1.53 × 10⁻⁴ S cm⁻¹ at 25 and 80 °C, respectively. Further addition of the ionic liquid 1-propyl-3-methylimidazolium iodine as a crystal growth inhibitor can effectively suppress the crystallization of the complex for more amorphous and smoother regions, which are much more conducive towards higher ion conductivity by the segmental motion of molecule chains. For application, the resulting device showed a power conversion efficiency of 5% and displayed excellent long-term stability. These results offer us more opportunities to explore simple and novel solid-state electrolytes for energy storage and conversion.