Accession Number : ADD007570

Title :   Method for Determining the Compensation Density in N-Type Narrow-Gap Semiconductors.

Descriptive Note : Patent,


Personal Author(s) : Bartoli,Filbert J ; Esterowitz,Leon ; Allen,Roger E ; Kruer,Melvin R

Report Date : 12 Aug 1980

Pagination or Media Count : 6

Abstract : A method for determining the compensation density of narrow-gap semiconductors. Photo-excited carriers are generated by uniformily irradiating a sample with a laser pulse of a particular density and pulse width for a particular time length and at a low sample temperature. The laser wavelength is chosen with a photon energy sufficiently high that carriers are excited from the conduction band by normal intrinsic absorption (one-photon absorption). Subsequent to the laser pulse, conductivity-voltage measurements are taken as a function of time during the photo-electron decay. Such measurements are made for different applied source-detector connections on the same sample with identical pulse-time values for each different correction. The sample is then laser-pulsed as before with a magnetic field normal to the sample surface to obtain Hall-voltage measurements. The measurements are averaged for the same time duration and the average of all curves are used in the determination. From the conductivity-voltage measurements and the Hall-voltage measurements, the mobility micron, and carrier density n, can be determined. The time dependence of micron and n measured during the photoelectron decay yields values of mobility as a function of n. A mobility vs carrier density curve is then prepared and compared with previously prepared curves to obtain a match and thereby determine the quality of the sample. Thus characterization of n-type narrow-gap semiconductors can be made. (Author)

Descriptors :   *Patent applications, *Current density, *N type semiconductors, *Narrow gap semiconductors, Charge carriers, Light pulses, Lasers, Excitation, Photons, Absorption, Electrical conductivity, Photoelectrons, Decay, Magnetic fields, Conduction bands, Temperature, Carrier mobility, Determination, Measurement, Time dependence

Subject Categories : Electricity and Magnetism
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE