Lucky-drift model for impact ionization in amorphous semiconductors

• Published in: Journal of materials science. Materials in electronics Vol. 20; no. Suppl 1; pp. 221 - 225
• Main Authors: Jandieri, K., Rubel, O., Baranovskii, S. D., Reznik, A., Rowlands, J. A., Kasap, S. O.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Boston Springer US 2009; Springer; Springer Nature B.V
• Subjects: Amorphous semiconductors; Applied sciences; Avalanches; Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed matter: structure, mechanical and thermal properties; Design. Technologies. Operation analysis. Testing; Electronics; Exact sciences and technology; Integrated circuits; Integrated circuits by function (including memories and processors); Ionization; Lattice dynamics; Materials Science; Mathematical models; Multiplication; Optical and Electronic Materials; Phonons in low-dimensional structures and small particles; Physics; Precursors; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductors; Switching; Impact Ionization; Avalanche Multiplication; Amorphous Semiconductor; Inelastic Scattering; Threshold Field; Prototype; Electronic switching; Amorphous semiconductors; Phonon; Impact phenomena; Amorphous state; Avalanche; Electric field; Non volatile memory; Amorphous hydrogenated material; Integrated circuit; Field ionization; Impact ionization; PCM material; Selenium; Electric field effect
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-007-9549-1

A lucky-drift model for impact ionization has been recently successfully used to account for avalanche phenomenon in amorphous selenium (a-Se). We extend the calculations in order to compare the effect in a-Se with possible impact ionization phenomenon in another prototype amorphous semiconductor: hydrogenated amorphous silicon (a-Si:H). The results suggest that the higher phonon energy in a-Si:H as compared to a-Se shifts the threshold field for impact ionization in a-Si:H to essentially higher fields than those needed for avalanche multiplication in a-Se. Furthermore, it has been recently suggested that impact ionization is a precursor of the switching effect in the phase-change-memory materials (Ge
2
Sb
2
Te
5
). We apply the lucky-drift model to Ge
2
Sb
2
Te
5
and show that it is capable to account for the magnitude of the electric field necessary to launch the electronic switching in this material.