Naughty Paul

The remarkable advances over the past few years in performance of photovoltaic cells, including the advent of new absorber materials, call for an update to the previous assessment of prospects for future progress. The same simple criteria with some refinements, based on cell and module performance data, serve to evaluate and compare most types of solar cells. Apart from Si and InP, for all types the “best cells” have improved in conversion performances (and crystalline Si modules have made major strides in cost reduction). New cell types, such as “perovskite”, sustainable chalcogenide, and quantum dot cells, are included. CdTe results bring those cells in line with other well-developed ones, lending some credence to the idea that the criteria provide the reader with knowledge, useful for gauging possible future technological developments. Additionally, the developments of the past few years show that, while the advent of more new cell types cannot be predicted, it can be aided and stimulated by innovative, daring, and creative new materials research.

The 2011–2013 period has seen amazing progress of nearly all solar-cell types that have possible or actual practical potential, including significant cost decreases of commercial cells. A concise update of the current status and future prospects of solar-cell research is given.

Multiple stacked InGaN/GaN quantum dots are embedded into an InGaN p-n junction to develop multilevel intermediateband (MIB) solar cells. An IB transition is evidenced from both experiment and theoretical calculations. The MIB solar cell shows a wide photovoltaic response from the UV to the near-IR region. This work opens up an interesting opportunity for high-efficiency IB solar cells in the photovoltaics field.

The discovery of graphene has created a great sensation in chemistry, physics, materials science, and related areas. The unusual properties of graphene have aroused interest in other layered materials, such as molybdenum sulfide and boron nitride. In the last few years, single- as well as few-layer as well as chalcogenides and other inorganic materials have been prepared and characterized by a variety of methods. These materials possess interesting properties, and some have potential applications. This Review provides an up-to-date account of these emerging two-dimensional nanomaterials. Not only are the synthesis and characterization covered, but also important aspects such as spectroscopic and optical properties, magnetic and electrical properties, as well as applications. Salient features of the composites formed from the layered inorganic structures with graphene and polymers are presented along with a brief description of borocarbonitrides.

Single and few-layer MoS₂, BN, and similar layered inorganic compounds are emerging as very interesting materials with numerous potential applications. This Review describes the synthesis and characterization of these graphene analogues and presents some of their physical properties and applications.