PHOTOCAPACITANCE EFFECTS IN ADDITIVELY COLORED ALKALI HALIDE CRYSTALS,
Abstract
Additively colored alkali halide crystals were placed between current blocking electrodes and an increase in the capacitance and conductance of the crystal was found on illumination. A measurement of these quantities at frequencies between 2 and 1000 c/s has shown that the observed behavior follows quite closely a linearized theory developed by J. Ross MacDonald. The region of application of the theory was examined experimentally, and results show that the theory may be used for larger applied voltages than assumed in the theory. An analysis of the experimental data indicates that the field induced electrode breakdown for the larger voltages (approx. 5 V r.m.s.) is of such a nature that the equivalent circuit describing the crystal continues to be valid. This has also been observed by others. Using the results of the theory the mobility of KI and KBr crystals at room temperature was measured. These determinations agree substantially with measurements by others using Hall effect methods. Measurements at low frequencies revealed phenomena due to the finite recombination rate of the conduction electrons and ionized F-centers. From an analysis of this behavior, the capture cross section of an ionized F-center in KBr was determined. The recombination rate constant in KBr was also measured. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 10, 1960
- Accession Number
- AD0612520
Entities
People
- A. J. Glass
- D. Kahn
Organizations
- Glenn L. Martin Company