Measurement of the bulk minority-carrier lifetime (T{sub b}) by optical methods, such as photocurrent decay or quasi-steady-state photoconductance (QSSPC), is strongly influenced by surface recombination. Several techniques are known to lower the effective surface recombination velocity, including the following: use of oxidation, floating N/P junction, SiN:H layer, HF immersion, and use of iodine in ethanol or methanol (I-E solution). Using I-E appears to be very simple and does not require any high-temperature treatment such as oxidation, diffusion, or nitridation processes, which can change T{sub b}. However, this is not a preferred procedure within the photovoltaic community because it is difficult to obtain same T{sub b} values reproducibly, particularly when the wafer lifetime is long. The objectives are: (1) Investigate various reasons why lifetime measurements may be irreproducible using I-E solution passivation. (2) Study the influence of the strength of iodine in the ethanol solution, wafer-cleaning procedures, influence of the wafer container during lifetime measurements, and the stability of I-E. (3) Compare lifetimes of wafers (having different T{sub b}) by various techniques such as QSSPC and transient photoconductive decay using short laser pulses of different light intensity; (4) Make minority-carrier diffusion length (L) measurements by a surface photovoltage technique, and to use T{sub b} and L data to determine diffusivity (D) values for various impurity and defect concentrations, using the relationship L{sup 2} = D* T{sub b}
