Organic−inorganic lead halide perovskite solar cells are potential alternatives to commercial silicon solar cells because of their attractive photon conversion efficiency and general material costs, except for the widely adopted organic hole-transporting polymers, which are currently expensive and have low conductivity. Inorganic hole-transporting layers (HTLs) have recently garnered attention due to their excellent stability and relatively effective cost. Nickel oxide (NiO x ) is a typical p-type oxide semiconductor with a deep valence band (VB) and is expected to be used as HTL. Unfortunately, the charge extraction efficiency has been hindered by its poor conductivity, resulting in lower efficiency when compared with organic HTL-based devices. Here, we report a new solutionprocessed doping strategy for NiO x with zinc dopant to improve its conductivity for perovskite solar cells. The NiO x :Zn HTL showed high transparency and significantly enhanced electrical conductivity in comparison with the pristine NiO x . Our best NiO x :Zn-based P-i-N planar device showed an efficiency of 19.6% with negligible hysteresis, which is comparable with the reported planar solar cell with an organic HTL. Moreover, the NiO x :Zn-based perovskite device displayed distinguished stability in ambient conditions. This paper demonstrated important progress toward high-efficiency planar perovskite devices with low-cost inorganic HTLs.

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Drought stress is an important environmental factor limiting productivity of plants, especially fast growing species with high water consumption like poplar. Abscisic acid (ABA) is a phytohormone that positively regulates seed dormancy and drought resistance. The PYR1 (Pyrabactin Resistance 1)/ PYRL (PYR-Like)/ RCAR (Regulatory Component of ABA Receptor) (PYR/PYL/RCAR) ABA receptor family has been identified and widely characterized in Arabidopsis thaliana. However, their functions in poplars remain unknown. Here, we report that 2 of 14 PYR/PYL/RCAR orthologues in poplar (Populus trichocarpa) (PtPYRLs) function as a positive regulator of the ABA signal transduction pathway. The Arabidopsis transient expression and yeast two-hybrid assays showed the interaction among PtPYRL1 and PtPYRL5, a clade A protein phosphatase 2C, and a SnRK2, suggesting that a core signalling complex for ABA signaling pathway exists in poplars. Phenotypic analysis of PtPYRL1 and PtPYRL5 transgenic Arabidopsis showed that these two genes positively regulated the ABA responses during the seed germination. More importantly, the overexpression of PtPYRL1 and PtPYRL5 substantially improved ABA sensitivity and drought stress tolerance in transgenic plants. In summary, we comprehensively uncovered the properties of PtPYRL1 and PtPYRL5, which might be good target genes to genetically engineer drought-Resistant plants.

Diamond is a wide-bandgap semiconductor possessing exceptional physical and chemical properties with the potential to miniaturize high-power electronics. Whereas boron-doped diamond (BDD) is a well-known p-type semiconductor, fabrication of practical diamond-based electronic devices awaits development of an effective n-type dopant with satisfactory electrical properties. Here we report the synthesis of n-type diamond, containing boron (B) and oxygen (O) complex defects. We obtain high carrier concentration (∼0.778 × 1021 cm−3) several orders of magnitude greater than previously obtained with sulfur or phosphorous, accompanied by high electrical conductivity. In high-pressure high-temperature (HPHT) boron-doped diamond single crystal we formed a boron-rich layer ∼1–1.5 μm thick in the {111} surface containing up to 1.4 atomic % B. We show that under certain HPHT conditions the boron dopants combine with oxygen defects to form B–O complexes that can be tuned by controlling the experimental parameters for diamond crystallization, thus giving rise to n-type conduction. First-principles calculations indicate that B3O and B4O complexes with low formation energies exhibit shallow donor levels, elucidating the mechanism of the n-type semiconducting behavior.

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Materials combining the hardness and strength of diamond with the higher thermal stability of cubic boron nitride (cBN) have broad potential value in science and engineering. Reacting nanodiamond with cBN at moderate pressures and high temperatures provides a pathway to such materials. Here we report the fabrication of Cx-BN nanocomposites, measuring up to 10 mm in longest dimension, by reacting nanodiamond with pre-synthesized cBN in a large-volume press. The nanocomposites consist of randomly-oriented diamond and cBN domains stitched together by sp3-hybridized C-B and C-N bonds, leading to p-type semiconductivity. Dislocations near the sutures accommodate lattice mismatch between diamond and cBN. Nanotwinning within both diamond and cBN domains further contributes to a bulk hardness ~50% higher than sintered cBN. The nanocomposite of C2-BN exhibits p-type semiconductivity with low activation energy and high thermal stability, making it a functional, ultrahard substance.

In this paper, the graphitic mixtures of C and BN have been subjected to high pressure and high temperature (HPHT) conditions to study the crystallization of the cubic phase, and new diamond crystals doped with B and N atoms (BC x N) were successfully synthesized with iron and nickel as catalysts. The morphology and characterization of our obtained diamond changed significantly, which was attributed to the incorporation of the B and N atoms into the crystal structure. In addition, we detected that the cubic phases obtained in the C0.9(BN)0.1 system were separated because of the different B/N ratio, while in the C0.5(BN)0.5 system no phase separation was found and the obtained “BCN” diamond exhibited cuboctahedral shape, light yellow in color, and nearly transparent. According to our results, two possible reaction routes were introduced for the crystallization of diamond in the graphitic mixtures of C and BN. Moreover, X-ray diffraction (XRD), Raman spectrum, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy were used to confirm their chemical composition and atomic-level hybrid qualities. Our results show that new B−C−N compounds can be synthesized by doping B and N atoms in diamond crystals under HPHT conditions, and it may become a new effective method in the future study of the preparation of cubic B−C−N alloys.

Crystal Growth & Design ARTICLE diffusion on diamond crystallization and provides a lot of valuable information on the search for the genesis of natural diamond.