Role of Pressure in the Growth of Hexagonal Boron Nitride Thin Films from Ammonia-Borane
| Autor: | Koepke, Justin C., Wood, Joshua D., Carrion, Enrique A., Schmucker, Scott W., Chen, Yaofeng, Hewaparakrama, Jayan, Rangarajan, Aniruddh, Datye, Isha, Mehta, Rushabh, Liu, Ximeng, Chang, Noel N., Nienhaus, Lea, Haasch, Richard T., Gruebele, Martin, Girolami, Gregory S., Pop, Eric, Lyding, Joseph W. |
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| Rok vydání: | 2016 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1021/acs.chemmater.6b00396 |
| Popis: | We analyze the optical, chemical, and electrical properties of chemical vapor deposition (CVD) grown hexagonal boron nitride (h-BN) using the precursor ammonia-borane ($H_3N-BH_3$) as a function of $Ar/H_2$ background pressure ($P_{TOT}$). Films grown at $P_{TOT}$ less than 2.0 Torr are uniform in thickness, highly crystalline, and consist solely of h-BN. At larger $P_{TOT}$, with constant precursor flow, the growth rate increases, but the resulting h-BN is more amorphous, disordered, and $sp^3$ bonded. We attribute these changes in h-BN grown at high pressure to incomplete thermolysis of the $H_3N-BH_3$ precursor from a passivated Cu catalyst. A similar increase in h-BN growth rate and amorphization is observed even at low $P_{TOT}$ if the $H_3N-BH_3$ partial pressure is initially greater than the background pressure $P_{TOT}$ at the beginning of growth. h-BN growth using the $H_3N-BH_3$ precursor reproducibly can give large-area, crystalline h-BN thin films, provided that the total pressure is under 2.0 Torr and the precursor flux is well-controlled. Comment: 45 pages including the supporting information, in print at Chemistry of Materials 2016 |
| Databáze: | arXiv |
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