Inference on the Production Mechanism of ZnO Thin Films from Activated Water and Dimethylzinc Molecules

Hironobu Umemoto, Takuma Ishikawa, Yushin Nishihara, Kanji Yasui, Hiroshi Nishiyama, Yasunobu Inoue, Yusaku Kashiwagi, Mitsuru Ushijima
2013 Japanese Journal of Applied Physics  
The reaction of Zn(CH 3 ) 2 and activated H 2 O produced in a reaction of H 2 and O 2 on a Pt catalyst and effused from a nozzle was examined both experimentally and theoretically. This reaction has been shown to be effective in the preparation of high-quality ZnO films. Laser-induced fluorescence measurements showed that radical species, such as H atoms and OH radicals, do not play major roles. The rotational temperature of H 2 O, measured with a coherent anti-Stokes Raman scattering
more » ... was 250 K. This low rotational temperature suggests that H 2 O molecules must be accelerated along the beam axis and that the collisional energy between Zn(CH 3 ) 2 and H 2 O is as high as 43 kJ mol -1 . This energy is higher than the potential barrier to produce HOZnCH 3 +CH 4 , 38 kJ mol -1 , obtained by ab initio calculations at the MP2/LANL2DZ level of theory. HOZnCH 3 thus produced can be the strongest candidate ZnO film precursor.
doi:10.7567/jjap.52.096701 fatcat:ivdjr5ij4vhxjbe6wu3bbypubq