Growth and vacuum post-annealing effect on the structural, electrical and optical properties of Sn-doped In2O3 thin films
Nowadays, the fabrication of cheaper, thermodynamically stable and durable transparent semiconducting oxide-based thin films are on high demand to enhance the properties of optoelectronic, sensing and energy harvesting devices. It is well known that Sn-doped In2O3 (ITO) thin films are difficult to g...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2020 |
| País: | Brasil |
| Institución: | Universidade Estadual Paulista (UNESP) |
| Repositorio: | Repositório Institucional da UNESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unesp.br:11449/197222 |
| Acceso en línea: | http://dx.doi.org/10.1016/j.tsf.2020.138207 http://hdl.handle.net/11449/197222 |
| Access Level: | acceso abierto |
| Palabra clave: | Vacuum annealing Indium tin oxide Band gap energy Grain size effect Sheet resistance Sputtering |
| Sumario: | Nowadays, the fabrication of cheaper, thermodynamically stable and durable transparent semiconducting oxide-based thin films are on high demand to enhance the properties of optoelectronic, sensing and energy harvesting devices. It is well known that Sn-doped In2O3 (ITO) thin films are difficult to grow by direct current sputtering. However, in this work cost-effective Sn-doped In2O3 films are deposited onto borosilicate glass substrates using a direct current sputtering of metallic In/Sn-target. The film thickness was controlled by the deposition time. A post-deposition annealing of the films in a vacuum atmosphere was performed in order to control the structural, optical and electrical properties. The phase formation, crystallite grain sizes (D) and lattice parameters have been assessed from the X-ray diffraction data analysis. Cross-section Scanning electron microscope image analyses were performed in order to estimate the growth rate of thin films. A band gap energy closing was observed associated with relaxation process of the unit cell suggested by the monotonic reduction of the lattice constant. Besides, a low sheet resistance (44 Ohm/square) was obtained, which is comparable to the commercially available ITO films. Furthermore, a inverse-square dependence between the sheet resistance and the grain size was determined (R-sq similar to 1/D-2). The last was used to estimate the carrier concentration of the thicker film similar to 10(20) cm(-3), which is in agreement with the value obtained from the Hall measurement. |
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