Hydrogen Passivation of B-O Defects in Czochralski Silicon

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

“…This was supported by further evidence from our other ongoing research with substantial improvements in the lifetimes due to hydrogen passivation on a whole array materials such as n-type, gallium-and boron-doped Cz silicon wafers, as well as multi-crystalline silicon and quasi-mono-crystalline silicon materials. 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].…”

Hydrogen passivation of laser-induced defects for silicon solar cells

“…A thin thermal oxide layer was grown before the front and rear SiNx:H layers were deposited using an industrial Roth&Rau remote microwave PECVD system. An advanced hydrogenation process incorporating minority carrier injection was then applied with a peak temperature of approximately 620 °e to passivate surface and bulk defects within the device [25]- [27].…”

Eliminating Light-Induced Degradation in Commercial p-Type Czochralski Silicon Solar Cells

“…Despite evidence from numerous authors on the involvement of hydrogen [87,101,107,116], there has been some debate over the role of hydrogen in the regeneration process [80]. In particular, it has been suggested that thermal effects during fast firing and the impact of plasma processing are responsible for the permanent deactivation of the defects, rather than the introduction of hydrogen [72,121].…”

“…Minority carrier injection can be achieved by using illumination and can lead to substantial increases in the concentration of highly mobile and reactive H 0 [111,115]. Some studies have discussed the influence of modulating the charge state of B-O defects and hydrogen for the passivation of B-O defects [87,102,[116][117][118][119]. One study, in particular, demonstrated a correlation between the theoretically predicted concentrations of H 0 and the regeneration reaction rate using a quasi-Fermi based model [119], highlighting the critical role of manipulating hydrogen charge states to increase the concentration of the minority hydrogen charge species to enable B-O defect passivation.…”