Title :
Calibration factors for lifetime measurements on Si ingots with a localized PCD method [solar cell fabrication]
Author :
Wang, T.H. ; Ciszek, T.F. ; Zhang, Y.
Author_Institution :
Nat. Renewable Energy Lab., Golden, CO, USA
Abstract :
The relationship between measured effective lifetime τe and bulk lifetime τb of minority carriers in silicon ingots by a localized photoconductance decay method has been determined with a full 3-dimensional and transient finite-element analysis. For an excitation light with a spot size of 3 mm ×1 mm and an absorption coefficient of 100 cm-1, the ratio of τ e to τb ranges from 0.95 at τb=1 μs and a surface recombination velocity S=102 cm/s to 0.573 at τb=100 μs and S=10 8 cm/s. This effect originates from both surface recombination and carrier diffusion from a localized light excitation
Keywords :
calibration; carrier lifetime; elemental semiconductors; finite element analysis; minority carriers; semiconductor device manufacture; semiconductor device measurement; semiconductor device models; semiconductor device testing; silicon; solar cells; surface recombination; time measurement; 3-D finite-element analysis; Si; Si ingots; Si solar cell fabrication; absorption coefficient; bulk lifetime; calibration factors; carrier diffusion; effective lifetime; excitation light; lifetime measurements; localized PCD method; localized light excitation; localized photoconductance decay method; minority carriers; surface recombination; surface recombination velocity; Absorption; Calibration; Laser beams; Optical pulses; Photoconductivity; Poisson equations; Probes; Silicon; Surface emitting lasers; Transient analysis;
Conference_Titel :
Photovoltaic Specialists Conference, 2000. Conference Record of the Twenty-Eighth IEEE
Conference_Location :
Anchorage, AK
Print_ISBN :
0-7803-5772-8
DOI :
10.1109/PVSC.2000.915846
