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

Electrically pumped lasing has been one of the most challenging issues for random lasers. Since holes are rare in most semiconductors, hole injection is necessary for electrically pumped lasers. Here in this article, by employing p-type diamond synthesized via a temperature gradient method under high-pressure and high-temperature conditions as a hole source, electrically pumped random lasing has been observed from p-Mg 0.35 Zn 0.65 O∕n-ZnO core-shell nanowire structures. The mechanism for the lasing can be attributed to the recombination of the electrons in the nanowires with the holes injected from the p-type diamond. Fig. 6. Room temperature EL spectra of the p-Mg 0.35 Zn 0.65 O∕ n-ZnO core-shell nanowire heterostructures with p-type diamond as the hole source layer under different injection currents. The inset shows the dependence of the integrated emission intensity of the device on the injection current.

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A series of diamond crystals doped with hydrogen is successfully synthesized using LiH as the hydrogen source in a catalyst-carbon system at a pressure of 6.0 GPa and temperature ranging from 1255 • C to 1350 • C. It is shown that the high temperature plays a key role in the incorporation of hydrogen atoms during diamond crystallization. Fourier transform infrared micro-spectroscopy reveals that most of the hydrogen atoms in the synthesized diamond are incorporated into the crystal structure as sp 3 -CH 2 -symmetric (2850 cm −1 ) and sp 3 CH 2 -antisymmetric vibrations (2920 cm −1 ). The intensities of these peaks increase gradually with an increase in the content of the hydrogen source in the catalyst. The incorporation of hydrogen impurity leads to a significant shift towards higher frequencies of the Raman peak from 1332.06 cm −1 to 1333.05 cm −1 and gives rise to some compressive stress in the diamond crystal lattice. Furthermore, hydrogen to carbon bonds are evident in the annealed diamond, indicating that the bonds that remain throughout the annealing process and the vibration frequencies centred at 2850 and 2920 cm −1 have no observable shift. Therefore, we suggest that the sp 3 C-H bond is rather stable in diamond crystals.