A Non-Destructive Method for Measuring Lifetimes for Minority Carriers in Semiconductor Wafers Using Frequency-Dependent ac Photovoltages

Chusuke Munakata, Noriaki Honma, Haruo Itoh

Japanese Journal of Applied Physics · 1983 · 27 citations · 12 references

Concepts

Abstract

A chopped photon beam, whose wavelength was 1.15 µm, irradiated a Si p-n junction (solar cell) through a transparent electrode and a mylar sheet. The chopping frequency was varied from 2 Hz through 200 kHz. Ac photovoltages were capacitively measured while changing the frequency. On a logarithmic scale, there appeared two bending points on the photovoltage vs frequency curve. Using the frequency at the second bending point, the lifetime for minority carriers in the substrate wafer was obtained. The observed value of 5.1 µs agreed well with that of 5.5 µs obtained by the conventional wavelength-dependent photocurrent method.

References

12