Study On The Fabrication And Photoelectric Properties Of The Transparent Conducting Film Based On SnO₂

Doped tin oxide （SnO₂） films have been widely used as transparent conducting electrodes in manyoptoelectronic and electro-optic devices such as solar cells and flat panel displays due to their highelectrical conductivity and high optical transmittance in the visible, and high infrared reflectance.Compared to the more widely used indium tin oxide （ITO）, SnO₂films are inexpensive, chemically stablein acidic and basic solutions, thermally stable in oxidizing environments at high temperatures, and alsomechanically strong, which are important attributes for the fabrication and operation of solar cells. Manydopants, such as antimony （Sb）, arsenic （As）, phosphorus （P）, indium （In）, molybdenum （Mo）, fluorine （F）,and chlorine （Cl）, have been studied to improve the electrical and optical properties of SnO₂films．However，looking for new materials still remains interesting and attractive．1. In this thesis，Sb-doped SnO₂ceramic targets were made with SnO₂powder with the purity of99.5%and Sb2O3powder with the purity99%. The SnO₂and Sb2O3powder were put in agate morear andadd some agglomerant to the powder, then whet them exiguous and uniform. Then, the powder is moveinto the die arrangment and press to moulding, and then the PVA were removed by heating. Last, thetargets were put in the chamber furnace and sintered to the ceramic targets.2. Sb-doped SnO₂（ATO） films have been prepared on glass and quzrtz substrates by pulsed larserdeposition （PLD） using Sb₂O₃-SnO₂ceramic targets with different Sb contents. Though the comparativestudy of growth pressure, substrate temperature and other parameters on the crystallinity, electrical andoptical properties, suitable process parameters for growing ATO films have been found and optimized. Anda good repeatability has been realized. The obtained film deposited in the optimized condition exhibited quite good optical and electrical properties with a high transmittance above83%, a resistivity of about1.0×103·cm, a hall mobility of greater than20cm2/Vs, and electron concentration of about3.0×103cm-3.3. SnO₂/Ag/SnO₂tri-layer thin films were prepared on quartz glass substrates by simultaneous RFmagnetron sputtering of SnO₂and dc magnetron sputtering of Ag. The influence of Ag thickness onelectrical and optical properties of the multilayer was investigated. Several analytical tools such as Hallmeasurements, four-point probes and ultraviolet-visible-near infrared （UV-Vis-NIR） spectrophotometerwere used to explore the causes of the changes in electrical and optical properties. The film had a figure ofmerit of1.6×10-2-1, the resistivity is4.8×10-5·cm, and the sheet resistance is9.61/sq, while theaverage transmittance is still as high as83%in the visible light region for thickness of Ag.4. SnO₂/Ag/SnO₂tri-layer thin films were prepared on glass substrates and PET substrates bysimultaneous RF magnetron sputtering of SnO₂with different O2/Ar ratio and DC magnetron sputtering ofAg, Several analytical tools such as Hall measurements, four-point probe and ultraviolet-visible-nearinfrared （UV-Vis-NIR） spectrophotometer were used to explore the causes of the changes in electrical andoptical properties. When O2/Ar ratio is1:14, the film had a figure of merit of1.69×10-2-1, the resistivity is9.8×10-5·cm, and the sheet resistance is9.68/sq, while the average transmittance is still as high as84%in the visible light region.