The temperature dependence of the electrical dark conductivity of microcrystalline Si was measured. Rapid thermal cooling resulted in an increase of the dark conductivity by 2 orders of magnitude below 300K. This frozen-in state was metastable: annealing and slow cooling restores the temperature dependence of the relaxed state. The time and temperature dependence of the relaxation of the dark conductivity revealed that two processes were competing. At short times the dark conductivity increases while at long times the dark conductivity decreases. The latter process was due to the dissociation of bond-center H complexes.

Hydrogen-Induced Metastable Changes in the Electrical Conductivity of Microcrystalline Silicon. N.H.Nickel, M.Rakel: Physical Review B, 2002, 65[4], 041301 (4pp)