Avalanche ionization in amorphous semiconductors

Using the results of a previous treatment of hot electrons in amorphous semiconductors, the avalance ionization coefficient, α, has been calculated as a function of the electric field. The Shockley hot-electron model was used. Because there is no conservation of crystal momentum, the threshold for electron-hole pair production is lower than it would be in a crystal of the same energy gap, and above the threshold the probability per unit time for pair production is quadratic in the energy. The results for α has been used to calculate the current-voltage relation for avalanche injection, and to study the avalanche process as a mechanism for switching.