Electrical properties for poly-Ge films fabricated by pulsed laser annealing

Electrical properties of 50-nm-thick polycrystalline germanium (poly-Ge) films fabricated by pulsed laser annealing were investigated. Analysis of the electrical conductivity using a numerical calculation program revealed that the density of defect states at grain boundaries in the poly-Ge films was a low of 1.1 × 1012 cm− 2 in contrast to a high density of 2.6 × 1013 cm− 2 in the case of laser crystallized poly-Si films. Transient photoconductivity measurements using pulsed laser irradiation revealed that 50-nm-thick poly-Ge films had a long carrier lifetime of 3.0 μs.