Graphene and related 2D materials offer an ideal platform for next generation disruptive technologies and in particular the potential to produce printed electronic devices with low cost and high throughput....

A simple and fast “top‐down” protocol is introduced herein to prepare solution processable few‐layer phosphorene nanosheets using vortex fluidic mediated exfoliation under near‐infrared (NIR) pulsed laser irradiation. This novel shear‐exfoliation method requires short processing times and produces highly crystalline, atomically thin phosphorene nanosheets (4.3 ± 0.4 nm). The as‐prepared phosphorene nanosheets are used as an effective electron transporting material (ETM) for low‐temperature processed, planar n‐i‐p perovskite solar cells (PSCs). With the addition of phosphorene, the average power conversion efficiency (PCE) increases from 14.32% to 16.53% with a maximum PCE of 17.85% observed for the phosphorene incorporated PSCs which is comparable to the devices made using the traditional high‐temperature protocol. Experimental and theoretical (density‐functional theory) investigations reveal the PCE improvements are due to the high carrier mobility and suitable band energy alignment of the phosphorene. The work not only paves the way for novel synthesis of 2D materials, but also opens a new avenue in using phosphorene as an efficient ETM in photovoltaic devices.

Graphene oxide (GO) sheets have been used as the surfactant to disperse single walled carbon nanotubes (CNT) in water to prepare GO/CNT electrodes which are applied on silicon to form a heterojunction which can be used in solar cells. GO/CNT films with different ratios of the two components and with various thicknesses have been used as semitransparent electrodes and the influence of both factors on solar cell performance has been studied. The degradation rate of the GO/CNT-silicon devices in ambient conditions has also been explored. The influence of the film thickness on device performance is found to be related to the interplay of two competing factors, namely the sheet resistance and transmittance. CNTs help to improve the conductivity of the GO/CNT film while GO is able to protect the silicon from oxidation in the atmosphere.

In the quantum world, a single particle can have various degrees of freedom to encode quantum information. Controlling multiple degrees of freedom simultaneously is necessary to describe a particle fully and, therefore, to use it more efficiently. Here we introduce the transverse waveguide-mode degree of freedom to quantum photonic integrated circuits, and demonstrate the coherent conversion of a photonic quantum state between path, polarization and transverse waveguide-mode degrees of freedom on a single chip. The preservation of quantum coherence in these conversion processes is proven by single-photon and two-photon quantum interference using a fibre beam splitter or on-chip beam splitters. These results provide us with the ability to control and convert multiple degrees of freedom of photons for quantum photonic integrated circuit-based quantum information process.