Title :
Signal formation in a-Si:H particle detectors
Author :
Hamel, L.A. ; Dubeau, Jacques ; Pochet, T. ; Equer, B.
Author_Institution :
Lab. de Phys. Nucl. et Groupe des Couches Minces, Montreal Univ., Que., Canada
fDate :
4/1/1991 12:00:00 AM
Abstract :
The response of a hydrogenated amorphous silicon thin film p-i-n diode to protons is presented as a function of the applied bias. A typical pulse shape is also presented. These data are explained on the basis of a model whose main features are fast (<5 ns) electron collection and slow (a few microseconds) hole collection due to multiple trapping transport through the shallow gap states. The overall charge normalization yields a mean pair creation energy ∈p of 3.4-4.4 eV, comparable to 3.63 eV in crystalline silicon despite the larger 1.7-eV gap. To explain this result, a microscopic Monte Carlo calculation, taking into account the actual density of states in a-Si:H, is used to study the energy sharing between ionization and phonon production during hot carrier thermalization. This simulation yields a value of 4.3 eV for ∈p
Keywords :
Monte Carlo methods; nuclear electronics; p-i-n diodes; proton detection and measurement; semiconductor counters; Si:H; a-Si:H particle detectors; applied bias; charge normalization; crystalline; density of states; electron collection; energy sharing; hole collection; hot carrier thermalization; ionization; mean pair creation energy; microscopic Monte Carlo calculation; multiple trapping transport; phonon production; protons; pulse shape; shallow gap states; thin film p-i-n diode; Amorphous silicon; Charge carrier processes; Crystallization; Electron traps; P-i-n diodes; Protons; Pulse shaping methods; Radiation detectors; Semiconductor thin films; Shape;
Journal_Title :
Nuclear Science, IEEE Transactions on
