Preparation Of Silicon Films Solar Cells With Textured ZAO Films Electrode

Using a Zn target with 2wt% Al, ZnO:A(lZAO)thin films which were used on silicon thin film solar cells were deposited on glass substrate by mid-frequency pulsed magnetron sputtering. The influence of oxygen flow rate,substrate temperature,working pressure and sputtering power on the films were studied. The result indicated that: the resistivity of the thin films were best with the resistivity of 6.31×10-4?cm, carrier concentration of 8.7×1020/cm3 , Hall mobility of 12.8cm2V-1s-1 and the average optical transmission over 85% within visible light, when the substrate temperature was 220℃, the sputtering power was 80W, and working pressure was 332mPa.Textured ZAO films suitable for thin film solar cells were prepared by etching the smooth films in 0.5% diluted HCl. The preparation process of textured films had been researched by using SEM pictures. The result shown that the effect of the texture-etched thin films were improved as the substrate temperature being higher, sputtering power being smaller, working pressure being lower in given areas. The optimum technological parameters were determined, the flow rate of O2/Ar was 3.6sccm/12sccm, substrate temperature was 220℃, sputtering power was 80W, working pressure was 292.6mP, and liquor chroma was 0.5%.In addition, the textured ZAO films were used in thin film solar cells. The results indicate that : only the ZAO films which have smooth crater-like surface morphology and the excellent performance of photoelectric can enhance absorption of light and efficiency of cells. On the contrary, the films with bad surface morphology decreased cells conversion efficiency ,because those films'resistance increased.