1. By combining electrostatics with photoconductivity, Carlson had found the right basic concept.

2. Optical absorption and photoconductivity spectra of trapped electrons in -γ-irradiated 2,2,4-trimethylpentane (TMP)/2,2-dimethylbutane (DMB)/2-methyltetrahydrofuran (MTHF) mixture glasses at 77 K have been measured.

3. As the P concentration increases to a suitable quantity, the photoconductivity of the alloy en-hances 2-3 orders of magnitude and the conduction mechanism changes from P to N type.

4. A theoretical study is made of the photoconductivity of hot photoelectrons interacting with acoustic phonons in n-type germanium at low temperature, T = 4 K, when the equipartition of the energy of phonons is not obeyed.

5. Reasonably good agreement between experiment and theory could be obtained only if the two centers were assumed to be the photoconductivity sensitizing, double acceptor Zn−3/2, and the V−3/2 level due to the vacancy which is also a double acceptor.