The approach of a hydrophilic group grafted buffer layer (HGGBL) was investigated for perovskite growth to realize highly efficient inverted planar perovskite solar cells with superior reproducibility, negligible hysteresis and improved stability.

While p-type transparent conducting materials (TCMs) are crucial for many optoelectronic applications, their performance is still not satisfactory. This has impeded the development of many devices such as photovoltaics, sensors, and transparent electronics. Among the various p-type TCMs proposed so far, Cu-based oxides and oxychalcogenides have demonstrated promising results in terms of their optical and electrical properties. Hence, they are the focus of this current review. Their basic material properties, including their crystal structures, conduction mechanisms, and electronic structures will be covered, as well as their device applications. Also, the development of performance enhancement strategies including doping/co-doping, annealing, and other innovative ways to improve conductivity will be discussed in detail.

No abstract

Development of efficient transparent and conducting functionalities of p-type materials at low dimensions are extremely vital for thin film transistor (TFT) electronics and hole transport applications in solar cells. In this work, we report dimensionality effects on functionalities of p-type CuI films prepared from room temperature sputter deposited Cu3N and Cu precursors. For film thickness ranging from 300 to 35 nm, it is found that the hole density increasing with decreasing film thickness is corroborated by relative defect photo luminescence associated with the Cu vacancy shallow level, further endorsing the origin of p-type conductivity in CuI to Cu vacancies. These dimensionality dependent hole transport modulations associated with hole density enable to achieve transparent conducting properties with high light transmission >82% and figure of merit (FOM) over 2250 MΩ–1, the best performing among p-type films. At low dimensions with a film thicknesses below 35 nm, hole density shows a significant drop of two orders with transport being found to be mediated by a percolation mechanism. Structural and morphology studies reveal the formation of faceted two-dimensional nanoplates with growth preferred along (111) of the γ-phase and indeed interconnected to form percolation. CuI TFT devices fabricated in percolated nanoplate regions show a good p-type transistor performance with a current on/off ratio of 102 for a 25 nm channel, and the linear field effect mobility reached 4.8 cm2 V–1 s–1 for a 30 nm channel, being the best so far in CuI TFTs. Development of high mobility CuI TFTs using sputtering at room temperature as reported here offer great advantages for design of large area complementary devices. Further exploitation of two-dimensional nanoplates of CuI for construction of p–n junctions is potential for nanoelectronics.

Electronic regulation and structural engineering at the atomic level of electrocatalysts is of vital importance to a highly efficient oxygen evolution reaction (OER).