High-quality multi-crystalline silicon (mc-Si) grown by directional solidification using notched crucibles

An enhanced cooling design in directional solidification for high quality multi-crystalline solar silicon

“…Besides, from the corresponding EPD mapping, it could be observed that high lifetime areas also had a high percentage of twins. This was consistent with the previous reports [9][10][11] suggesting that the cooling condition for crystal-3 was useful in growing high quality mc-Si for solar cells. Though not shown here, the EPD in the twin area was one or two orders of magnitude lower, i.e., in the order of 10 3 -10 4 /cm 2 , than that in elsewhere.…”

“…Three p-type mc-Si crystals were grown under different initial cooling conditions by changing or adjusting the cooling setup at bottom of the crucible. The casting furnace is the same as that reported before [10,11], but a new enhanced cooling design, as illustrated as Fig. 1(a), was used.…”

“…The solar cells fabricated from the material also showed higher quantum efficiency. Li et al [11] further proposed using a notched-crucible for grain control and selection to get high quality mc-Si. Recently, Nakajima et al [12] proposed a cooling pad with different thermal conductivities to control the dendrite arrangement in the dendritic casting method.…”

Grain control in directional solidification of photovoltaic silicon

“…More importantly, it was not limited to the crucible size. The cooling pad design for the control of supercooling using argon or water and the use of a notched crucible, as a self-seeded growth, have also been proposed [16,25], and the results are promising. The instantaneous cooling using argon flow was found effective and safe, and /110S and /112S dendrites were induced dominantly [16].…”

Evaluation of defects generation in crystalline silicon ingot grown by cast technique with seed crystal for solar cells

“…[1][2][3][4][5] In addition, growth techniques for obtaining large grains and to suppress impurities and crystalline defects have been proposed. [6][7][8] Fabricating an ingot that has relatively large grains with few grain boundaries has thus become possible. However, even in large grains, intra-grain defects that also deteriorate the conversion efficiency of solar cells may occur.…”