Lifetime And Diffusion Length Of Photogenerated Minority Carriers In Single-Crystalline N-Type Beta-Fesi2 Bulk

We have evaluated the lifetime and diffusion length of photogenerated minority carriers (holes) in single-crystalline n-type beta-FeSi2 bulk grown by chemical vapor transport. The diffusion length measured by optical-beam-induced current agreed well with that measured by electron-beam-induced current, that is, 51 and 38 mu m, respectively, for samples annealed at 800 degrees C for 8 h. The decay curve of photoconductivity obtained by 1.31 and 1.55 mu m light pulses was well fitted by assuming a carrier lifetime of approximately a few microseconds. The mobility of photogenerated minority carriers was estimated to be approximately 200-360 cm(2)/V s from the measured lifetime and diffusion length. (C) 2008 American Institute of Physics.