TY - JOUR
T1 - Refined dielectric breakdown model for crystalline organic insulators
T2 - Electro-thermal instability coupled to interband impact ionization
AU - Lima, A. M.N.
AU - Neto, A. G.S.Barreto
AU - Melcher, E. U.K.
AU - Neff, H.
N1 - Funding Information:
eW would like to thank CNPq, CAPES and CETENE/LINCS for the financial support. One of us (HN) is indebted to H. R. Zeller for originally launching an industrial research program on dielectric breakdown in 1985, where part of the experimental work has beenperformed at the former BBC (now ABB) Research Center in Baden-Daettwil, Switzerland. eW thank all reviewers for their comments and suggestions, which were very helpful for improving the quality of our manuscript.
PY - 2011/8
Y1 - 2011/8
N2 - A refined, substantially improved dielectric breakdown model is presented and applied to solution grown, single crystalline alkane type polymeric (n-C36H74) insulator, representing the iso-electronic analog to polyethylene. Ultraviolet illumination of attached electrodes allows controlled generation, injection into and transport of free charge carriers through the insulator. At sufficiently high electric fields, carrier transport is mediated by delocalized states in the conduction and valence band, respectively. At low and moderate fields, charge transport is suppressed by carrier trapping effects. Electric field induced inter-band impact ionization and generation of electron-hole pairs has been identified from these experiments as the dominant carrier multiplication and breakdown triggering mechanism. Critical field magnitudes >1.26 MV/cm have been recorded experimentally for injected electrons and >0.8 MV/cm for defect electrons, in reasonable agreement with the theoretical model. Application of the energy conservation principle, in accord with the solid state band model, allows determination of critical fields from the insulators electronic band-gap, effective mass and mobility of minority charge carriers. The related electrical breakdown feature and associated rapid dynamic temperature evolution has been explored on basis of the electro-thermal heat balance equation, following previous concepts applied to phase transitions. The non-linear differential equation has been solved numerically, using appropriate thermo-physical materials parameters, while considering the dielectric breakdown phenomenon as a singularity of the solution. Thermal and current run-away is due to strong positive electro-thermal feedback, in connection with an initial transient resistive behavior. Very small thermo-physical parameters are attributed to and explain filamentary charge transport. The temporal evolution of temperature and current in the conducting section or filament during the breakdown event exhibits a time scale up to the microsecond range. Shock wave emission is apparent, since the spatial temperature propagation exceeds the velocity of sound
AB - A refined, substantially improved dielectric breakdown model is presented and applied to solution grown, single crystalline alkane type polymeric (n-C36H74) insulator, representing the iso-electronic analog to polyethylene. Ultraviolet illumination of attached electrodes allows controlled generation, injection into and transport of free charge carriers through the insulator. At sufficiently high electric fields, carrier transport is mediated by delocalized states in the conduction and valence band, respectively. At low and moderate fields, charge transport is suppressed by carrier trapping effects. Electric field induced inter-band impact ionization and generation of electron-hole pairs has been identified from these experiments as the dominant carrier multiplication and breakdown triggering mechanism. Critical field magnitudes >1.26 MV/cm have been recorded experimentally for injected electrons and >0.8 MV/cm for defect electrons, in reasonable agreement with the theoretical model. Application of the energy conservation principle, in accord with the solid state band model, allows determination of critical fields from the insulators electronic band-gap, effective mass and mobility of minority charge carriers. The related electrical breakdown feature and associated rapid dynamic temperature evolution has been explored on basis of the electro-thermal heat balance equation, following previous concepts applied to phase transitions. The non-linear differential equation has been solved numerically, using appropriate thermo-physical materials parameters, while considering the dielectric breakdown phenomenon as a singularity of the solution. Thermal and current run-away is due to strong positive electro-thermal feedback, in connection with an initial transient resistive behavior. Very small thermo-physical parameters are attributed to and explain filamentary charge transport. The temporal evolution of temperature and current in the conducting section or filament during the breakdown event exhibits a time scale up to the microsecond range. Shock wave emission is apparent, since the spatial temperature propagation exceeds the velocity of sound
KW - Dielectric breakdown
KW - crystalline organic insulators
KW - electro-thermal instability
KW - impact ionization
UR - http://www.scopus.com/inward/record.url?scp=80051725074&partnerID=8YFLogxK
U2 - 10.1109/TDEI.2011.5976093
DO - 10.1109/TDEI.2011.5976093
M3 - Article
AN - SCOPUS:80051725074
SN - 1070-9878
VL - 18
SP - 1038
EP - 1045
JO - IEEE Transactions on Dielectrics and Electrical Insulation
JF - IEEE Transactions on Dielectrics and Electrical Insulation
IS - 4
M1 - 5976093
ER -
