Non-ohmic electrical conductivity of β-rhombohedral boron in high electric fields

摘要: Abstract The low-field conductivity of β-rhombohedral boron follows Mott's law variable-range hopping. Recent improvements in the energy band scheme attribute hopping centers to specific, partly occupied states gap, evoked by structural defects, particular unoccupied B(13) sites. Band type is also possible, after valence electrons have been excited into gap states. An experimental tool gain an insight transport mechanism semiconductors field-dependence electrical conductivity. For interpretation such experiments various theories are at disposal: classical model hot electrons, Poole-Frenkel model, models non-thermally activated Mott and Shklovskii, Model small polarons mobility, space-charge-limited currents. New measurements temperature range 187–303 K field strength up 8 k V cm−1 presented discussed according above-mentioned together with a critical review previous other authors. Three ranges be distinguished. (i) Up about 200 V cm−1: ohmic behavior; (ii) between 200 V cm−1 20 kV cm−1: non-ohmic behavior temperature-dependent field-dependence; (iii) above “electrical breakdown” I:E2 independent temperature.