Performance Of The Mo Thin Film Back Electrode By Magnetron Sputtering For CIGS Solar Cells

Now, copper indium gallium selenium (CIGS) thin film solar cells is one of the most prospects for the development of thin film solar cells by virtue of its high photoelectric conversion efficiency, no recession, stable performance, low cost and its attach more people is attention. In2010, the German hydrogen and solar research organizations (ZSW) has been successfully CIGS thin film solar cell laboratory record conversion efficiency and flushed to20.3%. In a long period of time, the researchers were also set on a wave of researches boom. Back electrode was an important part of the CIGS thin film solar cells, and the choice of materials related to the performance of the battery. Mo thin film because of the low electrical resistivity, good thermal stability, and with the CIGS layer may be formed in a good ohmic contact, while having a glass and CIGS similar coefficient of thermal expansion characteristics, the preferred material of the back electrode of the CIGS thin film solar cells.The experiments were prepared by using magnetron sputtering technology. The Mo film sputtering power is divided into bipolar pulse power and frequency power. Bipolar pulsed magnetron sputtering deposition in the ordinary slide Mo film target for round Mo target, In order to study the structure of the Mo film morphology and optoelectronic properties, I decided to change the sputtering time, substrate temperature and sputtering power. For the sake of analysis the sputtering power and pressure influence on the structure and morphology and optoelectronic properties, I used the twin target frequency magnetron sputtering deposition of Mo films on a200×200mm flat glass, target a rectangular Mo target.The results showed that the Mo film that deposited by the bipolar pulsed magnetron, and the technological conditions as followthe sputtering time was60min, the substrate temperature was100℃and the sputtering power was60W, the film having a (211) crystal planes preferential growth and grains were columnar growth, clear grain boundary reflectivity of about55%in the10-5Ω·cm resistivity. Meanwhile the Mo film that deposited by IF magnetron sputtering, having a (110) plane of preferential growth, the columnar growth of grains, and that crystal particles become larger with the sputtering power increases, the degree of crystalline of the Mo thin film becomes good, while the resistivity of the film did not change a little, the value was up to10-5Ω·cm; With the deterioration of the working pressure increasing, the crystallization of the Mo film becoming larger, the crystal particles becoming smaller and the thin film own low reflectivity, the value was up to10-5Ω·cm. The results revealed that the Mo films were accord with requirements of the back electrode performance.