Title :
The effect of the variation in resistivity and lifetime on the solar cells performance along the commercially grown Ga- and B-doped Czochralski ingots
Author :
Meemongkolkiat, Vichai ; Nakayashiki, Kenta ; Rohatgi, Ajeet ; Crabtree, Geoffrey ; Nickerson, Jeff ; Jester, Theresa L.
Author_Institution :
Sch. of Electr. & Comput. Eng., Georgia Inst. of Technol., Atlanta, GA, USA
Abstract :
A systematic study of the variation in resistivity and lifetime on cell performance, before and after light-induced degradation (LID), was performed along the B- and Ga-doped Czochralski (Cz) ingots. Screen-printed solar cells with Al-back surface field were fabricated and analyzed from different locations on the ingots. Despite the large variation in resistivity (0.57 Ω-cm to 2.5 Ω-cm) and lifetime (100-1000 μs) in the Ga-doped Cz ingot, the efficiency variation was found to be ≥0.5%. No LID was observed in the cells fabricated from the Ga-doped ingot. In contrast with the Ga-doped ingot, the B-doped ingot showed a very tight resistivity range (0.87 Ω-cm to 1.22 Ω-cm), resulting in very tight lifetime and efficiency distributions. However, the LID effect reduced the efficiency of these B-doped cells by about 1.1% absolute. Additionally, the use of thinner substrate and higher resistivity B-doped Cz is shown to effectively reduce the LID effect.
Keywords :
boron; crystal growth from melt; electrical resistivity; elemental semiconductors; gallium; ingots; segregation; silicon; solar cells; 100 to 1000 mus; Czochralski ingots; Si:B; Si:Ga; efficiency distributions; lifetime; light-induced degradation; resistivity; screen-printed solar cells; solar cells; Conductivity; Degradation; Doping; Etching; Lighting; Manufacturing industries; Photoconductivity; Photovoltaic cells; Tail; USA Councils;
Conference_Titel :
Photovoltaic Specialists Conference, 2005. Conference Record of the Thirty-first IEEE
Print_ISBN :
0-7803-8707-4
DOI :
10.1109/PVSC.2005.1488331