Dependence of the activation energy of conductivity on the compensation degree in germanium

Abstract

Some changes of the activation energy el of the conductivity of Ge which are produced by variations of the compensation ratio K are studied in the region of temperatures where the conductivity is related to electrons released from shallow donors into the conduction band. A substantial increase of el is found for shallow donor concentrations of about

Photoluminescence of heavily doped and compensated germanium

“…We have investigated a series of n-type germanium bulk crystals doped with shallow impurities of As ( N A , = (5 to 7 ) x 1017 c~l -~) and compensated with Ga by the use of nuclear transmutations during thermal neutron irradiation [7]. The compensation K , which is a function of the irradiation dose, was controlled by Hall effect measurements both a t room temperature and 77 K. We have excited bulk emission with monochromatic light.…”

“…1 shows the steady-state luminescence of samples with different compensation degree a t 4.2 K. With increasing compensation the emission maximum shifts to longer wavelengths, the emission intensity strongly decreases, and the halfwidth of the luminescence band increases. (1) < 0.1, (2) 0.28, (3) 0.60, (4) 0.74, (5) 0.91, (6) 0.97 (overcompensated to p-type Ge), (7) 0.99 2 10' 2 @Z -c (1) where f is the modulation frequency and A the intensity ratio. The time constant calculated from (1) represents the mean value for the time t = l/Zf.…”