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We discuss results of our investigations toward understanding bulk and surface components of light-induced degradation (LID) in low-Fe c-Si solar cells. The bulk effects, arising from boron-oxygen defects, are determined by comparing degradation of cell parameters and their thermal recovery, with that of the minority-carrier lifetime (τ) in sister(More)
We have determined that mechanisms of irreproducibility in measurement of lifetime arise from two sources: (i) improper wafer cleaning, and (ii) instability of I-E solution when in contact with a Si wafer. This paper describes a sequential optical oxidation and chemical cleaning procedure that can reproducibly yield the correct values of bulk lifetime. We(More)
We have measured and compared surface roughness and the degree of damage for wafers cut by three different sawing techniques - slurry, Ni-based diamond wire, and resin-based diamond wire sawing. The local damage was determined by angle polishing followed by defect etching, TEM, SEM/EBSD imaging and Raman imaging. It showed that each of the cutting processes(More)
Solar cells fabricated on boron (B)-doped Czochralski (Cz) Si wafers in the photovoltaic industry are known to suffer from light-induced degradation (LID) in efficiency. This paper reports on promising LID-free large-area indium (In)-doped Cz Si solar cells. Two different commercial-grade B-doped Cz materials were included for comparison. To study the(More)
Measurement of the minority carrier lifetime (&#x03C4;) of high-quality wafers (having bulk minority carrier lifetime, &#x03C4;<sub>b</sub> &gt; few milliseconds) requires surface passivation with very low surface recombination velocity, typically &lt;; 1cm/s. Furthermore, for mapping large (e.g., 156 x156 mm) wafers, the passivation must also be stable and(More)
The injection-level dependent (ILD) lifetime of the silicon bulk material impacts the cell characteristics in multiple and underappreciated ways. Fill factor, FF, is commonly attributed to cell resistances but not to ILD lifetime. Most of the non-ideality behavior, m, and the J<sub>02</sub>, of a commercial p-type PERC cell with rear AlO<sub>x</sub>(More)
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