Accession Number : AD0693887

Title :   DIFFUSION AND LUMINESCENCE OF RARE EARTHS IN CADMIUM SULFIDE.

Descriptive Note : Interim technical rept.,

Corporate Author : OHIO STATE UNIV RESEARCH FOUNDATION COLUMBUS ELECTRONIC MATERIALS AND DEVICES LAB

Personal Author(s) : Girton,Dexter G.

Report Date : JUN 1969

Pagination or Media Count : 154

Abstract : The technique of diffusion is shown to solve the major problems of producing rare earth doped CdS. In this method, an undoped CdS crystal, excess S (or Cd), and 5 mg of rare earth metal were sealed in a 3.6 cc. quartz ampoule at about 2 x 10 to the 5th power torr. Diffusions were performed with excess S for pressures ranging from 3.3 atm. to 33 atm. and temperatures ranging from 800C to 1050C, and with 6 atm. excess Cd at 960C. Diffusions were also performed with ZnSe crystals, excess Se, and 5 mg rare earth. The presence of rare earths in the diffused CdS (and ZnSe) samples was detected by observing the photoluminescent emission at 77K. The emission Pr, Nd, Ho, Er, Tm and Yb in CdS, and Ho, Er, Tm, and Yb in ZnSe has been observed and the spectra are shown. For given temperature, time, and chalcogen pressure the spectral characteristics were very reproducible from run to run, and the emission intensity for Nd, Er, and Yb in CdS was as high or higher than the best vapor phase doped crystals we have grown. A luminescent profile technique has been developed which measures the rare earth luminescent intensity as a function of depth from the surface of diffused samples. Photoluminescence measurements of Yb in CdS as a function of depth gave a profile which was neither a Gaussian nor complementary error function. Part of the profile appears to arise from a fast component of the diffusion and the other part from a slow diffusing component. (Author)

Descriptors :   (*CADMIUM SULFIDES, *DOPING), (*RARE EARTH ELEMENTS, LUMINESCENCE), DIFFUSION, ZINC COMPOUNDS, SELENIDES, SEMICONDUCTORS, VAPORS, THESES

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE