TECHNOLOGY FOR THE PRODUCTION OF 20 EFFICIENCY C-SI SOLAR CELLS FOR CONCENTRATING SYSTEMS

摘要

In the present work we have investigated the best working-conditions applied to crystalline silicon technology developed in ENEA laboratories to transfer the concentration solar cell technology from lab-scale to pre-pilot level. We have realized different devices using FZ p-type Boron doped wafers and varying the sheet resistance of the emitters aiming at analyzing the effects of junction depth and concentration on the surface of doped elements affecting the recombination process. The very high current level of this kind of devices (Jsc: 1 up to 8 A/cm{sup}2) imposed the use of thick fingers/busbar on the contacting structure in order to reduce the ohmic losses. Our aim is to develop a process easily transferable to industrial scale. A simplified photolitographic sequence to realize a thick layer of photoresist (>15 μm) followed by evaporation was used. We made a comparative study of the electrical behavior of different devices (current-voltage and quantum efficiency characterization) at one sun and under concentrated light, to investigate the influence of different fabrication conditions on the electrical performances of the devices. The best result achieved is η > 19% at 100 suns.