Titanium Films by Sol-Gel Process Doped Yb3+ and Er3+: thermal treatment effect

The search for clean and renewable energy sources has been constantly studied to reduce environmental damage caused by energy generation. Solar radiation is a reality to generation of the electric energy, but part this energy is not used to produce electricity. This work aims to study the preparation of thin films based on titanium doped with Yb3+ and Er3+, the spin-coating technique was used setting the parameters; rotation at 3000rpm, volume alkoxide doped with lanthanide ions 50μL, acceleration and deceleration ramps 10 seconds, and the maximum rotation for 30 seconds. The study relates two thermal treatments in order to promete the upconversion mechanism, so in the one the films were submitted at 500ºC for 4h between the depositions and in the another, first all the depositions were carried out and to finalize the heat treatment in the conditions. The films without thermal treatment presented about 72% transparency from 350nm, after thermal treatment 83%. The X-rays diffraction showed begin crystallization of the Ti02 (JCPDS#23-1446). The emission spectra of the films excited at 980nm showed the emission characteristic of the Er3+ ion in the regions green (542nm) and red (660nm), corresponding to the transitions 4S3/2 --> 4I15/2 and 4F9/2 --> 4I15/2, respectively. The emission intensity is a function of the laser power, as shown in Figure 1 a. However, the thermal treatment between depositions promoted decrease of the emission intensity, figure 1 b.