ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
A new methodology involving the measurement and integration of photoconductivity decay (PCD) of carriers is developed to separate surface recombination velocity (S), Shockley–Read–Hall lifetime (τSRH), trap-assisted Auger (Bt), and band-to-band Auger (C) recombination coefficients in semiconductors. Conventional differentiation methodology used in the past not only suffers from the potential errors due to the differentiation of the digitized injection level versus decay time transient, N=f(t), but also from the difficulty in assessing errors in the recombination coefficients because the lifetime models or equations are used to fit the differentiated data, τeff(N), rather than the raw experimental data [N=f(t)]. In this new methodology, first a mathematical equation is derived by integration of the general lifetime expression with various recombination coefficients to express the carrier decay time as a function of injection level, t=f(N). The Levenberg–Marquardt numerical method is then used to fit this mathematical equation to the raw experimental data (N,t) for rapid and accurate assessment of τSRH, Bt, and C. Finally, the PCD lifetime measurements are performed on a few silicon samples to demonstrate the validity and advantages of the integration approach over the differentiation methodology in separating and quantifying recombination mechanisms in silicon.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.354215
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