Choi Young Joong, Lee Ho Yun, Kim Seohan, Song Pung Keun
Department of Materials Science and Engineering, Pusan National University, Busan 46241, Korea.
Department of Materials Science and Engineering, Ångström Laboratory, Uppsala University, 75321 Uppsala, Sweden.
Nanomaterials (Basel). 2021 Sep 11;11(9):2363. doi: 10.3390/nano11092363.
Amorphization using impurity doping is a promising approach to improve the thermoelectric properties of tin-doped indium oxide (ITO) thin films. However, an abnormal phenomenon has been observed where an excessive concentration of doped atoms increases the lattice thermal conductivity (). To elucidate this paradox, we propose two hypotheses: (1) metal hydroxide formation due to the low bond enthalpy energy of O and metal atoms and (2) localized vibration due to excessive impurity doping. To verify these hypotheses, we doped ZnO and CeO which have low and high bond enthalpies with oxygen, respectively, into the ITO thin film. Regardless of the bond enthalpy energy, the values of the two thin films increased due to excessive doping. Fourier transform infrared spectroscopy was conducted to determine the metal hydroxide formation. There was no significant difference in wave absorbance originating from the OH stretching vibration. Therefore, the increase in due to the excessive doping was due to the formation of localized regions in the thin film. These results could be valuable for various applications using other transparent conductive oxides and guide the control of the properties of thin films.
利用杂质掺杂实现非晶化是改善锡掺杂氧化铟（ITO）薄膜热电性能的一种很有前景的方法。然而，已经观察到一种异常现象，即掺杂原子浓度过高会增加晶格热导率（）。为了阐明这一矛盾，我们提出了两个假设：（1）由于氧和金属原子的键焓能低而形成金属氢氧化物；（2）由于杂质掺杂过多而导致局部振动。为了验证这些假设，我们分别将具有低键焓和高键焓的ZnO和CeO与氧掺杂到ITO薄膜中。无论键焓能如何，由于掺杂过多，两种薄膜的值都增加了。进行傅里叶变换红外光谱以确定金属氢氧化物的形成。源于OH伸缩振动的波吸收率没有显著差异。因此，由于掺杂过多导致的增加是由于薄膜中形成了局部区域。这些结果对于使用其他透明导电氧化物的各种应用可能是有价值的，并指导薄膜性能的控制。
