TY - JOUR
T1 - The impact of Ge codoping on the enhancement of photovoltaic characteristics of B-doped Czochralski grown Si crystal
AU - Arivanandhan, Mukannan
AU - Gotoh, Raira
AU - Watahiki, Tatsuro
AU - Fujiwara, Kozo
AU - Hayakawa, Yasuhiro
AU - Uda, Satoshi
AU - Konagai, Makoto
N1 - Funding Information:
This work was financially supported by a Grant-in-Aid for Young Scientists B (No. 22760005) from the Ministry of Education, Culture, Sports, Science and Technology of Japan. This work was also supported by the Inter-university Cooperative Research Program of the Institute of Materials Research, Tohoku University, Japan.
PY - 2012/2/15
Y1 - 2012/2/15
N2 - The effect of Ge codoping on minority carrier lifetime in boron (B)-doped Czochralski-silicon (CZ-Si) crystals was investigated. The minority carrier lifetime increased from 110 to 176 s as Ge concentration was increased from zero to 1 10 20cm -3 in B/Ge codoped CZ-Si crystals. Light-induced degradation (LID) experiments showed that B-doped CZ-Si degrades rapidly, while B/Ge codoped CZ-Si degrades more slowly. Moreover, the flow pattern defect (FPD) density of grown-in micro-defects (GMD) in as-grown B/Ge codoped CZ-Si decreased with increasing Ge concentration. From the infrared (IR) absorption studies, it was observed that the interstitial oxygen (O i) concentration decreased as Ge concentration increased in the crystal. The suppressed LID effect in the B/Ge codoped CZ-Si appears to be related to the low concentration of B-O associated defects, possibly because Ge doping retards the O i diffusion in addition to the low O i concentration present (evidenced from IR studies). The mechanism by which the Ge concentration influences the reduction of FPDs and O i concentration is discussed in terms of Ge-vacancy defect formation during post-growth cooling of the ingots.
AB - The effect of Ge codoping on minority carrier lifetime in boron (B)-doped Czochralski-silicon (CZ-Si) crystals was investigated. The minority carrier lifetime increased from 110 to 176 s as Ge concentration was increased from zero to 1 10 20cm -3 in B/Ge codoped CZ-Si crystals. Light-induced degradation (LID) experiments showed that B-doped CZ-Si degrades rapidly, while B/Ge codoped CZ-Si degrades more slowly. Moreover, the flow pattern defect (FPD) density of grown-in micro-defects (GMD) in as-grown B/Ge codoped CZ-Si decreased with increasing Ge concentration. From the infrared (IR) absorption studies, it was observed that the interstitial oxygen (O i) concentration decreased as Ge concentration increased in the crystal. The suppressed LID effect in the B/Ge codoped CZ-Si appears to be related to the low concentration of B-O associated defects, possibly because Ge doping retards the O i diffusion in addition to the low O i concentration present (evidenced from IR studies). The mechanism by which the Ge concentration influences the reduction of FPDs and O i concentration is discussed in terms of Ge-vacancy defect formation during post-growth cooling of the ingots.
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U2 - 10.1063/1.3687935
DO - 10.1063/1.3687935
M3 - Article
AN - SCOPUS:84857824401
SN - 0021-8979
VL - 111
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 4
M1 - 043707
ER -
