TY - JOUR
T1 - Effects of Laser Photolysis of Hydrocarbons at 193 and 248 nm on Chemical Vapor Deposition of Diamond Films
AU - Constantin, Loic
AU - Fan, Lisha
AU - Azina, Clio
AU - Keramatnejad, Kamran
AU - Silvain, Jean Francois
AU - Lu, Yong Feng
N1 - Funding Information:
The authors gratefully appreciate the financial support from the National Science Foundation (CMMI 1265122) and the Nebraska Center for Energy Sciences Research (NCESR). In addition, the authors would like to express their appreciation to Dr. D. R. Alexander in the Department of Electrical & Computer Engineering at the University of Nebraska-Lincoln for providing convenient access to the SEM. Manufacturing and characterization analyses were performed at the NanoEngineering Research Core Facility (part of the Nebraska Nanoscale Facility), which is partially funded by the Nebraska Research Initiative.
Funding Information:
The authors gratefully appreciate the financial support from the National Science Foundation (CMMI 1265122) and the Nebraska Center for Energy Sciences Research (NCESR). In addition, the authors would like to express their appreciation to Dr. D. R. Alexander in the Department of Electrical & Computer Engineering at the University of Nebraska-Lincoln for providing convenient access to the SEM. Manufacturing and characterization analyses were performed at the NanoEngineer-ing Research Core Facility (part of the Nebraska Nanoscale Facility), which is partially funded by the Nebraska Research Initiative.
Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/4/4
Y1 - 2018/4/4
N2 - In this work, the influence of ultraviolet (UV) laser photolysis of hydrocarbons on combustion chemical vapor deposition of diamond films was investigated at 193 and 248 nm. Although the output fluence of the 193 nm laser was 1 order of magnitude lower than that of the 248 nm laser, UV laser irradiations at 193 and 248 nm led to similar enhancement of diamond growth: a 2-fold increase in the diamond deposition rate and a 3% increase in diamond quality compared to those obtained without laser irradiation. In situ thermionic measurement of emission currents revealed that the diamond nucleation time was reduced from 9.5 min without laser irradiation to 4.2 and 7.0 min, respectively, with UV laser irradiations at 193 and 248 nm. These results suggest the advantages of using UV laser photolysis in diamond deposition achieved by suppressing nondiamond carbon accumulation. Spectroscopic investigation of the flame chemistry showed that UV laser irradiations of the diamond-forming combustion flames led to photogenerated reactive species, OH, CH, and C2, which play critical roles in diamond growth. The more pronounced flame chemistry change and diamond growth enhancement with UV laser irradiation at 193 nm than 248 nm is attributed to a higher photon energy, 6.4 eV, which is above the energetic dissociation threshold of most hydrocarbons for more efficient photodissociation.
AB - In this work, the influence of ultraviolet (UV) laser photolysis of hydrocarbons on combustion chemical vapor deposition of diamond films was investigated at 193 and 248 nm. Although the output fluence of the 193 nm laser was 1 order of magnitude lower than that of the 248 nm laser, UV laser irradiations at 193 and 248 nm led to similar enhancement of diamond growth: a 2-fold increase in the diamond deposition rate and a 3% increase in diamond quality compared to those obtained without laser irradiation. In situ thermionic measurement of emission currents revealed that the diamond nucleation time was reduced from 9.5 min without laser irradiation to 4.2 and 7.0 min, respectively, with UV laser irradiations at 193 and 248 nm. These results suggest the advantages of using UV laser photolysis in diamond deposition achieved by suppressing nondiamond carbon accumulation. Spectroscopic investigation of the flame chemistry showed that UV laser irradiations of the diamond-forming combustion flames led to photogenerated reactive species, OH, CH, and C2, which play critical roles in diamond growth. The more pronounced flame chemistry change and diamond growth enhancement with UV laser irradiation at 193 nm than 248 nm is attributed to a higher photon energy, 6.4 eV, which is above the energetic dissociation threshold of most hydrocarbons for more efficient photodissociation.
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U2 - 10.1021/acs.cgd.8b00084
DO - 10.1021/acs.cgd.8b00084
M3 - Article
AN - SCOPUS:85045022416
VL - 18
SP - 2458
EP - 2466
JO - Crystal Growth and Design
JF - Crystal Growth and Design
SN - 1528-7483
IS - 4
ER -