Role of rare-earth elements in the design of radiation detectors and electroluminescent sources

Rare-earth (RE) elements present in the growth from the liquid phase have purifying effect on III-V semiconductors due to RE's high affinity towards chemical species of shallow impurities. We demonstrate this purifying effect on the preparation of InP-based structures by liquid phase epitaxy with Pr admixture to the growth melt. We employ low temperature photoluminescence, capacitance-voltage and temperature dependent Hall effect measurements to show that optimized concentration of Pr admixture results in the growth of high purity layers of both conductivity types. We discuss the application of p-type InP layers in radiation detectors and InGaAsP layers in electroluminescent sources.