Organic–inorganic hybrid perovskites have created enormous expectations for low-cost and high-performance optoelectronic devices. In prospect, future advancements may derive from reaping novel electrical and optical properties beyond pristine perovskites through microscopic structure design and engineering. Herein, we report the successful preparation of two-dimensional inverse-opal perovskite (IOP) photonic films, featuring unique nanostructures and vivid colors. Further compositional and structural managements promise optical property and energy level tunability of the IOP films. They are further functionalized in solar cells, resulting in colorful devices with respectable power conversion efficiency. Such concept has not been previously applied for perovskite-based solar cells, which could open a route for more versatile optoelectronic devices.

The broken symmetry of Janus nanostructures (JNs) provides a distinctive means to express drastically different chemical and physical characters within a single particle and acquire emergent properties usually inconceivable for homogeneous or symmetric nanostructures. In spite of their tremendous application potential, considerable challenges are encountered in identifying pathways to synthesize or assemble JNs with a controllable geometry and morphology. Here, we exploit the reverse process of growth, i.e. silver etching, to quantitatively control the structural and optical properties of the DNA-mediated Au–Ag JNs. The transmission electron microscopy and optical measurements, along with numerical simulations, present a comprehensive view of the etching dynamics and a detailed analysis of the influencing factors that provide handles for regulating the silver etching rate and progress. In addition, a novel type of composite JN is proposed and a model system is designed and engineered through dynamical control of the etching and DNA-hybridization processes.

The quantum dot sensitized solar cell (QDSSC), which has an analogous structure and working principle to the dye sensitized solar cell, has drawn much attention due to its characteristic advantages like ease of fabrication, robustness and the potential for multiple electron generation. Much effort to optimize various components of QDSSCs has been taken to boost the overall device performance. It is well known that the counter electrode (CE) plays a vital role in sensitized solar cells and could profoundly impact the device performance. Recently, metal chalcogenides have been explored as superb counter electrode materials for QDSSCs. This review gives a panorama of both conventional noble metals and carbon CEs and newly emerged metal chalcogenide CE materials for QDSSCs, while the influence of CE materials on the overall device performance is stressed in detail. The Conclusions and prospects emphasizes the importance of studies on metal chalcogenide CE materials and puts forward the remaining challenges that need to be addressed.

Here we present an in-depth and comprehensive study of the effect of the geometry and morphology of nanoarray (NA) substrates on their surface-enhanced Raman scattering (SERS) performance. The high-quality SERS-active NA substrates of various unit shapes and pitches are assembled through electron beam lithography and fabricated by electron beam physical vapor deposition. Good agreement is found on comparing the Raman scattering results with the integrals of the fourth power of local electric fields from the three-dimensional numerical simulations. A novel type of hybrid NA substrate composed of disordered nanoparticles and a periodic NA is fabricated and characterized. The morphology of NAs has little influence on the SERS performance of hybrid NA substrates and they perform better than both their counterparts pure NA and disordered nanoparticle substrates.

The quantum dot sensitized solar cell (QDSSC), which has an analogous structure and working principle to the dye sensitized solar cell, has drawn much attention due to its characteristic advantages like ease of fabrication, robustness and the potential for multiple electron generation. Much effort to optimize various components of QDSSCs has been taken to boost the overall device performance. It is well known that the counter electrode (CE) plays a vital role in sensitized solar cells and could profoundly impact the device performance. Recently, metal chalcogenides have been explored as superb counter electrode materials for QDSSCs. This review gives a panorama of both conventional noble metals and carbon CEs and newly emerged metal chalcogenide CE materials for QDSSCs, while the influence of CE materials on the overall device performance is stressed in detail. The Conclusions and prospects emphasizes the importance of studies on metal chalcogenide CE materials and puts forward the remaining challenges that need to be addressed.