Sweepout and Dielectric Relaxation in Compensated Extrinsic Photoconductors
- 15 June 1971
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 3 (12), 4312-4330
- https://doi.org/10.1103/physrevb.3.4312
Abstract
Experimental evidence is presented concerning sweepout of majority carriers in -type doped germanium photoconductors under high-resistivity conditions where the dielectric relaxation time exceeds the recombination time. This evidence demonstrates sweepout at signal modulation frequencies lower than the inverse dielectric relaxation time for the case of dc photoconductive gain greater than unity and gain saturation for signal modulation frequencies greater than the inverse dielectric relaxation time. These experimental findings are shown to be in general agreement with the predictions of a theoretical approach to semiconductor transport in this regime based upon the frequency dependence of the Debye length in compensated extrinsic photoconductors. This approach calculates the spatial dependence of the photoinduced hole concentration in the sample for an assumed boundary condition of at the anode. This dependence is then used to predict an approximate maximum gain-bandwidth product in the form . Lack of exact agreement between theoretical curves and experimental results can be explained by postulating an inhomogeneity in sample resistivity.
Keywords
This publication has 9 references indexed in Scilit:
- FREQUENCY DEPENDENCE OF THE DEBYE LENGTH IN COMPENSATED EXTRINSIC PHOTOCONDUCTORSApplied Physics Letters, 1970
- Response Characteristics of Extrinsic PhotoconductorsJournal of Applied Physics, 1969
- Relaxation Phenomena in High-Resistivity Ge:HgJournal of Applied Physics, 1967
- Photoexcited Electron Capture by Ionized and Neutral Shallow Impurities in Silicon at Liquid-Helium TemperaturesPhysical Review B, 1966
- Carrier generation and recombination processes in copper-doped germanium photoconductorsJournal of Physics and Chemistry of Solids, 1962
- Current-Carrier Transport with Space Charge in SemiconductorsPhysical Review B, 1961
- Polarization Processes in Partially Illuminated Photoconducting InsulatorsPhysical Review B, 1959
- Transient Behavior of the Ohmic ContactPhysical Review B, 1959
- Photoconductor Performance, Space-Charge Currents, and the Steady-State Fermi LevelPhysical Review B, 1959