Method for preparing nano luminescent material ZnO/SnO2 heterostructure

[0025] Example 1

[0026] Weigh a certain amount of Sn powder and Zn powder as source materials at a molar ratio of 1:1 and place them on the front of the alumina boat. Place a gold-plated silicon substrate 2cm away from the source material, and then place the alumina boat in the middle of the tube furnace , Add a refractory brick at each end of the pipe to cover (such as figure 1 ). Start the mechanical pump to make the pressure in the tube reach -0.08MPa, close the valve, and pass in an appropriate amount of argon. When the pressure in the tube reaches one atmospheric pressure, open the valve to connect to the atmosphere, start the mechanical pump again and repeat the above operation four times to remove the tube furnace cavity air. Start the furnace, raise the temperature to 950°C, pass in 50 sccm (volume flow unit, meaning milliliters per minute in standard conditions) oxygen, and keep it warm for 50 minutes. The furnace was naturally cooled to room temperature, the gas was turned off, the substrate was taken out, and a white product was obtained on the substrate. Observe the resulting product directly under the scanning electron microscope (e.g. figure 2 ), a large number of nanowires with a diameter of 50 to 100 nanometers and a length of about 10 microns can be found. image 3 The XRD analysis shows that the structure of the product consists of hexagonal ZnO and tetragonal SnO 2 The composition, formed a heterostructure, and the remaining diffraction peaks are the substrate and gold-plated components. Figure 4 The EDS spectrum of ZnO/SnO 2 The heterostructure contains Zn, Sn and O elements, which further proves that the product is ZnO/SnO 2 Heterostructure, where the Si peak is the substrate. Figure 5 It is the PL image of the product, where the smaller peak at 379 nm corresponds to the band-edge luminescence of ZnO. The excitation is due to the recombination of free excitons. This conclusion corresponds well to the XRD analysis. The broad peak at 505nm is due to SnO 2 The intervention caused the red shift of the defect emission peak. therefore, Figure 5 The presence of a relatively strong green light emission peak in the heterostructure indicates that there are a large number of defects related to oxygen vacancies in the heterostructure, which improves the light-emitting performance of a single oxide.

[0027] Example 2

[0028] As in Example 1, use an electronic balance to weigh a certain amount of Sn powder and Zn powder as the source material and place it on the front end of the alumina boat. Place a gold-plated silicon substrate 2 cm away from the source material, and then place the alumina boat in the tube furnace. In the middle part, add a refractory brick at each end of the pipe to cover (such as figure 1 ). Start the mechanical pump to make the pressure in the tube reach -0.08MPa, close the valve, and pass in an appropriate amount of argon. When the pressure in the tube reaches one atmospheric pressure, open the valve to connect to the atmosphere, start the mechanical pump again and repeat the above operation four times to remove the tube furnace cavity air. Start the furnace, raise the temperature to 950°C, pass in 50sccm oxygen, and keep it warm for 70 minutes. The furnace was naturally cooled to room temperature, the gas was turned off, the substrate was taken out, and a white product was obtained on the substrate. The morphology, structure, element composition and luminescence properties of the product are the same as those in Example 1.

[0029] Example 3

[0030] As in Example 1, use an electronic balance to weigh a certain amount of Sn powder and Zn powder as the source material and place it on the front end of the alumina boat. Place a gold-plated silicon substrate 2 cm away from the source material, and then place the alumina boat in the tube furnace. In the middle part, add a refractory brick at each end of the pipe to cover (such as figure 1 ). Start the mechanical pump to make the pressure in the tube reach -0.08MP, close the valve, and pass in an appropriate amount of argon. When the pressure in the tube reaches one atmosphere, open the valve to connect to the atmosphere, start the mechanical pump again and repeat the above operation four times to remove the tube furnace cavity air. Start the furnace, raise the temperature to 1050°C, inject 50sccm oxygen, and keep it warm for 50 minutes. The furnace was naturally cooled to room temperature, the gas was turned off, the substrate was taken out, and a white product was obtained on the substrate. The morphology, structure, element composition and luminescence properties of the product are the same as those in Example 1.