Impact of Hydrogen Concentration on the Regeneration of Light Induced Degradation

Large-Area n-Type PERT Solar Cells Featuring Rear p+ Emitter Passivated by ALD Al2 O3

“…Nonetheless, it has to be remarked that techniques based on the combined effect of temperature and carrier injection (as described in [57]) have demonstrated to be effective in providing a stable post-regeneration performance in p-type cells and that tool suppliers are starting to develop solutions for the integration of these regeneration steps into production lines. However, it has been recently suggested that hydrogen plays a fundamental role in the regeneration kinetics [58]- [60], which makes the effectiveness of the regeneration procedure also dependent on the adopted passivation scheme. This issue together with the increase to the CoO caused by the introduction of the regeneration steps has to be carefully evaluated by cell manufacturers when choosing whether to opt for n-type or p-type cell technology.…”

Influence of bound hydrogen states on BO-regeneration kinetics and consequences for high-speed regeneration processes

“…Herguth et al have shown that active BO related defects can be transformed into a recombination inactive state being stable under solar cell operating conditions by applying a regeneration procedure consisting of a combination of carrier injection and slightly elevated temperatures [10,11]. Recent results suggest that hydrogen might be the key factor to fast regeneration processes [12,13]: It has been shown, that if more hydrogen is introduced into the silicon bulk realized e.g. by choosing suitable hydrogenated dielectric surface coatings [14,15] and optimized high temperature steps during sample processing [16,17] the regeneration process becomes faster.…”

Hydrogen passivation of defect-rich n-type Czochralski silicon and oxygen precipitates

“…Such improvements have been related to a reduction in recombination activity of impurity related defects, laser-induced defects and crystallographic defects such as sliplines, grain boundaries and dislocation clusters [29,30,[50][51][52]. Many publications from other research groups have reported on the important influence of hydrogen in the generation and passivation of oxygen related defects such as boron-oxygen complexes, thermal donors and vacancy-oxygen complexes [17,28,32,[53][54][55].…”

“…For commercial grade solar cells, hydrogen also plays a vital role in passivating defects, such as the passivation of crystallographic defects and impurities in the bulk of multi-crystalline silicon solar cells [22][23][24][25][26][27] and boron-oxygen defects [17,[28][29][30][31][32]. Hydrogen passivation has also proved essential for high efficiency solar cells fabricated on high-lifetime FZ wafers, including the passivated emitter, rear and totally diffused (PERT) and the world record holding passivated emitter, rear and locally diffused (PERL) solar cell technologies, through enhanced surface passivation [33,34].…”