Development of Heterojunction Back Contact Si Solar Cells

An energy conversion efficiency of 25.1% was achieved in heterojunction back contact (HBC) structure Si solar cell utilizing back contact technology and an amorphous silicon thinfilm technology. A new patterning process was established, and it was applied to the fabrication process of HBC cells. In addition, the unique technology of the surface mount technology concept contributed to the superior performance of HBC cell. A short circuit current density (J_sc) and an open-circuit voltage (V_oc) were 41.7 mA/cm2 and 736 mV, respectively. The high J_sc as well as the high Voc indicates the strength of HBC structure cell. Besides, a high fill factor of 0.82 was obtained, which shows that HBC structure cell does not have any fundamental critical losses caused from series resistance or shunt resistance. Such high values of I-V parameter means that the patterning process was properly performed.