Improving the Quality of GaN Crystals by Using Graphene or Hexagonal Boron Nitride Nanosheets Substrate

Abstract

The progress in nitrides technology is widely believed to be limited and hampered by the lack of high-quality gallium nitride wafers. Though various epitaxial techniques like epitaxial lateral overgrowth and its derivatives have been used to reduce defect density, there is still plenty of room for the improvement of gallium nitride crystal. Here, we report graphene or hexagonal boron nitride nanosheets can be used to improve the quality of GaN crystal using hydride vapor phase epitaxy methods. These nanosheets were directly deposited on the substrate that is used for the epitaxial growth of GaN crystal. Systematic characterizations of the as-obtained crystal show that quality of GaN crystal is greatly improved. The fabricated light-emitting diodes using the as-obtained GaN crystals emit strong electroluminescence under room illumination. This simple yet effective technique is believed to be applicable in metal-organic chemical vapor deposition systems and will find wide applications on other crystal growth.

Impact of N-plasma and Ga-irradiation on MoS2 layer in molecular beam epitaxy

“…[1][2][3][4] In addition, 2D materials such as graphene, boron nitride nanosheets, and layered transition metal dichalcogenides (TMDs) were investigated as potential buffer layers for the epitaxial growth of III-V semiconductors on foreign substrates. [5][6][7][8] The use of TMDs, in particular, layered-MoS 2 as a buffer layer attracts the potential interest of researchers to address the issues such as large lattice and thermal expansion mismatch for the growth of GaN. 9,10 Recently, GaN epitaxy on layered-MoS 2 flakes was demonstrated using high temperature ($1000 C) growth process of metal-organic chemical vapor deposition (MOCVD).…”

Intrinsic Properties of Macroscopically Tuned Gallium Nitride Single‐Crystalline Facets for Electrocatalytic Hydrogen Evolution

“…Ramans catteringh as been extensively applied to study IIInitridesa nd is ap rovenm ethod fors tudying stress, which is an important factor for the energy band structure and phonon vibrations. [38][39][40] Figure1cs hows the Raman spectra of the differentc rystallographic facets of the GaN crystal.O nly E 2 (high) and A 1 (LO) phononb ands are observed on GaN (001) and GaN (00À1), and otherp honon peaks disappear.M eanwhile, the A 1 (TO), E 1 (TO) and E 2 (high) phononm ode bands appear simultaneously on the GaN (100) facet. These resultsc onform to the Ramans electionr ule.…”

In situ Electrochemical Transformation of Ni3S2 and Ni3S2‐Ni from Sheets to Nanodisks: Towards Efficient Electrocatalysis for Hydrogen Evolution Reaction (HER)

“…[1][2][3][4][5][6][7][8][9][10][11] Though, past few decades have witnessed significantly new advances in this direction, [12][13][14][15][16][17][18] the search for efficient hydrogen evolution pathways and novel catalysts that could lead to such pathways still continues. [19][20][21][22][23][24][25][26][27][28][29][30] Apart from the composition, the relation between the morphology/architecture of the catalyst and its property is quite intriguing and offers innumerable tweaking opportunities in the quest for better materials with enhanced hydrogen generation capabilities. [8,[31][32][33][34][35][36][37][38][39][40][41][42][43][44] In this context, less toxic nickel based materials have emerged as strong candidates as electro catalysts for the hydrogen evolution reaction (HER).…”