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Exciton Impact Ionization and Electric Conductivity in Germanium at Low Temperature
Author(s) -
Nöldeke Ch.,
Metzger W.,
Huebener R. P.,
Schneider H.
Publication year - 1985
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221290229
Subject(s) - exciton , impact ionization , ionization , electric field , atomic physics , excitation , germanium , luminescence , impurity , materials science , electrical resistivity and conductivity , doping , conductivity , biexciton , chemistry , condensed matter physics , optoelectronics , physics , silicon , ion , organic chemistry , quantum mechanics
The exciton luminescence intensity and the electric conductivity are measured simultaneously during optical excitation in high‐purity Ge and in p‐doped Ge at 4.2 K as a function of an applied electric field. With increasing field the exciton density decreases due to exciton impact ionization. The carriers which are set free by this process result in a distinct increase in the electric conductivity. For undoped Ge the results agree well with a rate equation model based on impact ionization of the excitons. In the p‐doped Ge impurity impact ionization is found to have a strong influence in addition to impact ionization of the excitons.