Incentivos para Publicaciones con Filiación a la UNSA, 2018-1
David Gregorio Pacheco Salazar
Objetivo
PUBLICAR ARTICULOS CON FILIACION A LA UNSA
Resumen:
.tPolycrystalline SnO2films with different thicknesses were successfully deposited on glass substrate atroom temperature using a DC sputtering technique. As-grown films showed the formation of an amor-phous SnO2phase, whereas the thermal annealed samples showed the formation of a SnO2rutile-typestructure. The structural study showed that the crystallinity of the annealed films was improved as a func-tion of film thickness. Scanning electron microscopy images of the annealed films unveiled the formationof cracked surfaces along with columnar growth, irrespective of the depositon time. Raman spectroscopymeasurements evidenced the presence of modes related to a surface disorder,a progressive strain reduc-tion and a crystallinity improvement. UV–vis data analysis indicates a reduction in the band gap energywith films thickness due to presence of strain states as confirmed by theoretical calcuations. It wasobserved that the strained states in the films affected the sensing response to a methane gas flow with abetter sensitivity for the thinner film.
Palabras clave
Transparent semiconductor oxides, Tin dioxide film, Rietveld refinement, DFT calculationsa
Problema central
Transparent semiconductor oxides (TSOs) play an importantrole in the development of new electronic devices based on thinfilms. TSOs materials can be used in diverse areas of the technologyas optoelectronic devices, transparent electrodes for liquid crystaldisplays (LCDs), organic light-emitting diodes (OLEDs), gas sen-sors and other applications [1,2]. Among them, the photovoltaicenergy production using dye solar cells is an outstanding appli-cation (based on TSOs) [3–5], because of the clean and renewableenergy production. Furthermore, the TSOs use lower cost raw mate-rials in comparison to the conventional silicon solar cell technology,which nowadays leads the largest market share On the other hand, the SnO2 is one of the more used transparentsemiconductor oxides, due to its abundance, chemical, mechani-cal, optical and electronic properties, which make this system apromising material for optical and gas sensing applications. Theroom-temperature band gap energy of bulk SnO2is Eg∼ 3.6 eV Since the photons energy of visible light ranges from 1.65 to 3.26 eV,the large band gap energy of SnO2limited some optical applica-tions.Nevertheless, several experimental and theoretical studiesshowed the possibility of the band gap tuning (band gap engineer-ing). For instance, the application of tensile strain in thin films canresult in a significant band gap reduction in SnO2, and that reduc-tion was associated with a disorder induced in the SnO6octahedra[8]. On the other hand, several methods have been used to grown tinoxide films such as chemical vapor deposition [9], dip-coating [10],spray pyrolysis [11], pulse laser deposition [12], RF sputtering [13]among others. The sputtering technique is an outstanding methodonce the films can be grown at room temperature, with good uni-formity and high reproducibility. However, the low-temperaturegrowth can introduce structural changes that can modifiy the opti-cal and gas sensing properties. In this work, a systematic study ofthe thickness dependence of the structural, vibrational, and opticalproperties of polycrystalline SnO2films grown at room tempera-ture on glass substrate using a DC sputtering technique is presented.The effect of the stress magnitude related to the film thickness onthe gas sensing response is also discussed.
Hipótesis planteada
It is posiible to grow, successfully polycrystalline SnO2 films withdifferent thicknesses on glass substrates at room temperatureby a sputtering technique.
Resultados esperados
Número de artículos científicos, con filiación UNSA, publicados y aceptados para publicación en revistas
indizadas durante el periodo del 2012 –2018.
Impactos esperados
Reposicionar a la UNSA en los rankings nacionales o internacionales de universidades.