Hot-electron induced electroluminescence and avalanche multiplication in hydrogenated amorphous silicon

Subpicosecond hot carrier cooling in amorphous silicon

“…[7][8][9] In an electric field F, the free electron energy gain per unit time is RϭeF 2 , where is the free carrier mobility. Taking ϭ6 cm 2 /V s, 15 the field required to overcome a cooling rate of 2 eV/ps is 6ϫ10 5 V/cm.…”

“…6 Only at fields higher than 10 6 V/cm have avalanche effects recently been observed. [7][8][9] One hypothesis for such a high threshold is that the carriers lose energy faster than they can be accelerated by the electric field.…”

Hot-electron degradation in hydrogenated amorphous-silicon-nitride thin-film diodes

“…This indicates that another mechanism is limiting the electron temperature at higher fields. For a-Si:H, the high-field scattering mechanism has recently been discussed by Toyama et al 8 Their observation of a threshold for the internal field strength of 1.0-1.2 MV/cm during hot-electron-induced electroluminescence indirectly implied the occurrence of impact ionization above these field strengths. They also demonstrate ͑their Fig.…”

“…Nieuwesteeg et al 6 identified a relationship between the production of hot electrons and the electrical drift under high electrical dc-field conditions at the anode of a-SiN x H y -based TFDs, used as a switching element in active-matrix liquid-crystal displays. Toyama et al 8 studied hot-electron-induced electroluminescence and avalanche multiplication in an ac-driven double-insulating a-Si:H device. Here, we investigate high-quality TFD structures, where it proves possible to directly probe the electronscattering mechanisms by investigating the a-SiN x H y thickness and field dependence of hot-electron production by spectral photon-emission microscopy ͑SPEM͒, and relate these findings to the electrical drift of the TFD.…”