Nb doping effect on TiO2−x films for bolometer applications

TiO2−x films for bolometer applications: recent progress and perspectives

“…A metal peak of titanium is observed in figure 13(a) when the pO 2 content is 4.3%., Whereas no rutile and anatase crystal structure when the pO 2 level is higher than 4.3% due to enough oxygen reacting with titanium atoms. The resistivity and TCR of Nb-doped TiO 2−x films are 0.05 Ω•cm and 1.88 -%/K, which are lower than those of other films [25]. The resistivity of Nb-doped and pure TiO 2−x samples varies from 0.39 to 2.48, and 0.82 to 42.65, respectively, with the increase of pO 2 .…”

“…The film was deposited at room temperature at a constant RF power of 300 W for 14 min. When the total flow rate is 50 sccm, the O 2 /(O 2 +Ar) ratio of the main combustion chamber varies from 4.3% to 4.8% [25].…”

“…The deposition rate decreased significantly when pO 2 ascended up to 4.8%. When the titanium target's reaction rate with oxygen is greater than the sputtering rate, the target's surface is completely oxidized, and the construction mode changes from the metal mode to the oxide mode [25]. A metal peak of titanium is observed in figure 13(a) when the pO 2 content is 4.3%., Whereas no rutile and anatase crystal structure when the pO 2 level is higher than 4.3% due to enough oxygen reacting with titanium atoms.…”

“…Recently, it has been reported that non-stoichiometric TiO 2−x films can be used as thermistor materials for the uncooled bolometer [23,24]. At the same time, through research, TiO 2−x has a good application in radiometers [25]. Therefore, scientists at home and abroad have made outstanding achievements in improving the electrical performance of titanium oxide materials.…”

“…They found that with the oxygen partial pressure increasing, the resistivity was increased, which resulted in the enhancement of TCR value for about 3.6 -%/K [22]. The Nb-doped TiO 2−x films showed a controllable resistivity, low 1/f noise parameter for 10 -12 , and relatively high TCR value for 3.1 -%/K [25]. Tanrikulu et al [26] synthesized the TiO 2−x thin films by atomic layer deposition grown at 150 °C and annealed at 300 °C, which has a very high TCR for 9 -%/K Ju et al [27,28] fabricated amorphous TiO 2−x thin films at room temperature by controlling the substrate temperature and oxygen partial pressure, the films' electrical properties could be adjusted with the O/Ti ratio changed from 1.73 to 1.97, and the TCR of the samples also varied from 1.2 to 2.3 -%/K.…”