Facile growth of aluminum oxide thin film by chemical liquid deposition and its application in devices

Abstract

Uniform and continuous Al2O3 thin films were prepared by the chemical liquid deposition (CLD) method. The breakdown field strength of the amorphous CLD-Al2O3 film is 1.74 MV/cm, making it could be used as a candidate dielectric film for electronic devices. It was further proposed to use the CLD-Al2O3 film as an electron blocking layer in a triboelectric nanogenerator (TENG) for output performances enhancement. Output voltages and currents of about 200 V and 9 µA were obtained, respectively, which were 2.6 times and 3 times, respectively, higher than TENG device without an Al2O3. A colloidal condensation-based procedure controlled by adjusting the pH value of the solution was proposed to be the mechanism of CLD, which was confirmed by the Tyndall effect observed in the growth liquid. The results indicated that the CLD could serve as a low-cost, room temperature, nontoxic and facile new method for the growth of functional thin films for semiconductor device applications.

Chemical Solution Deposition of Al(OH)3‐AlOOH Films: Application for Surface Sensitizing of Rigid and Flexible Substrates to Improve the Adhesion in Coating Technology Areas

“…This is particularly evident for the as-deposited film reported by Suárez-Campos et al [110] Regarding the annealed samples, it is also very important to note that the temperatures used were not enough to convert the deposited material into Al 2 O 3 compound. According to the interesting work reported by Rivas-Mercury et al, [105] who employed neutron thermodiffractometry to study the Al(OH) 3 to AlOOH and AlOOH to Al 2 O 3 transitions when starting from "pure" Al(OH) 3 , the Al(OH) 3 and AlOOH compounds are found in the same proportions at 360°C, while AlOOH and Al 2 O 3 are found in the same proportion at 500°C, which agrees with the similar studies reported by Yong et al [104] and Redoui et al [106] These results confirm that the annealing temperatures used by Suárez-Campos et al [110] and Li et al [111] were not enough to completely convert the as-deposited material into Al 2 O 3 . In fact, by considering the neutron thermodiffractometry data reported by Rivas-Mercury et al, [105] the material obtained by Li et al [111] after annealing at 400°C could be composed of about 20 % Al(OH) 3 and 80 % AlOOH, while the material obtained by Suárez-Campos et al [110] after the annealing process at 500°C could be composed of about 50 % AlOOH and 50 % Al 2 O 3 .…”

“…Despite the previous comments, we recognize that the formulations reported by Suárez-Campos et al [110] and Li et al [111] are excellent alternatives for the inexpensive synthesis of aluminum hydroxide/oxyhydroxide/oxide films in aqueous solutions. We particularly noted that the formulation reported by Suárez-Campos et al [110] is very simple and versatile, and it also confirms the effectiveness of the general formulation presented in Table 1 to chemical solution deposit metal hydroxides thin films (with a content of oxyhydroxide and oxide, as discussed in the present paper), since they used all the three reagents included in such general formulation.…”

“…It is important to mention that two very interesting related papers were reported by other authors during the review process of the present manuscript. These works were developed by Suárez-Campos et al [110] and Li et al, [111] who reported the synthesis of Al(OH) 3 thin films by chemical solution deposition and chemical liquid deposition, respectively, which were later converted into Al 2 O 3 films after an annealing process at 500°C and 400°C, respectively. Although both papers deal with technological applications of the synthesized materials, the chemical composition was determined in both cases only Table 6.…”

“…It is important to note that by carefully observing the spectra reported by Suárez-Campos et al [110] and Li et al, [111] it is deduced that they can be solved by introducing a nonnegligible content of AlOOH (compound omitted in both reports). This is particularly evident for the as-deposited film reported by Suárez-Campos et al [110] Regarding the annealed samples, it is also very important to note that the temperatures used were not enough to convert the deposited material into Al 2 O 3 compound.…”

“…This leads to the fourth drawback: they did not perform a TGA experiment to corroborate the chemical composition they reported. Therefore, it is convenient to redetermine the chemical compositions reported by Suárez-Campos et al [110] and Li et al [111] This is particularly relevant in the work reported by Suárez-Campos et al, [110] since they largely used the chemical compositions to discuss the properties and characteristics of the synthesized material.…”