TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The nanoparticles of the wide band gap semiconductor are silica nanoparticles. The nanocrystal semiconductor particles are titania nanoparticles. The nanocrystal composite film with multi-holes is a silica and titania composite film. The dye is N719 dye. Preferred Method: The step (i) comprises taking titania powder (5 g), mixing silica and titania (mass of silica is 2.5-15% of titania), adding acetic acid (1-2 ml), adding deionized water (5 ml) in five times by adding 1 ml per each time, adding absolute ethanol (15 ml) in 15 times by adding 1 ml per each time, adding ethanol (15 ml) in 6 times by adding 2.5 ml per each time, stirring for 3 minutes after each addition, adding absolute ethanol (100 ml) to obtain a slurry, stirring the slurry for 10 minutes by using magnetic force, where the stirring speed is 200-400 revolutions per minute, dispersing for 60 minutes by using ultrasonic waves, adding terpinol (20 g), repeating the stirring by using magnetic force and dispersing by using ultrasonic waves, adding ethylcellulose (3 g) and absolute ethanol (30 g), repeating stirring by using magnetic force and dispersing by using ultrasonic waves, rotating and distilling for 2-8 hours at 30-70 degrees C in a rotary evaporimeter. The step (ii) comprises dipping the conductive glass in titanium tetrachloride solution (20-300 mM) at 70 degrees C for 30 minutes, taking out and washing the titanium tetrachloride solution on the surface of the conductive glass with deionized water, drying, using a silk net printing and a 100-400 mesh silk net to print the titania doped with silica prepared in the step (i) on the conductive glass, stewing for 3 minutes, drying for 8 minutes at 125 degrees , repeating the printing process of the nanocrystal composite film with multi-holes, stewing and drying, firing at least for 15 minutes at 500 degrees C, cooling to room temperature, dipping in titanium tetrachloride solution (20-300 mM) at 70 degrees C for 30 minutes, taking out and washing the titanium tetrachloride solution on the surface of the conductive glass with deionized water, drying and placing in a muffle furnace for at least 5 minutes at 500 degrees C. The step (iii) comprises placing the nanocrystal composite film of titania doped with silica in a muffle furnace, heating for 30 minutes at 500 degrees C, placing in a N719 absolute ethanol solution (10-70 mM), taking out and using absolute ethanol to wash the dye on the surface and drying.