摘要:

A yellow‐orange luminescence which peaks at 6030 Å at 300 °K has been observed in (Mg, O)‐doped GaP and is attributed to a bound excitonic transition at a nearest‐neighbor Mg&sngbnd;O complex. A photoluminescent efficiency at low temperatures of ∼20% has been measured and yellow diodes of external quantum efficiency ≃0.1% at 77 °K have been fabricated.

ISSN:0003-6951    

DOI:10.1063/1.1654122

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Measurements are presented as a function of temperature, in several ferroelectric crystals with the tungsten bronze crystal structure, using forward Raman scattering (polaritons). These results determine the frequencies of TO and LO modes. Thus, the strengths of the optic modes and the frequency dependence of the dielectric constant &egr;(&ohgr;) can be determined. From these results, the low‐frequency clamped dielectric constant &egr;(0) surprisingly is found to be approximately independent of temperature toTc. We believe that the results indicate that these ferroelectrics do not have ``soft'' optic modes in the usual sense but are relaxers.

ISSN:0003-6951    

DOI:10.1063/1.1654123

出版商:AIP    

年代:1972

数据来源: AIP

ISSN:0003-6951    

DOI:10.1063/1.1654124

出版商:AIP    

年代:1972

数据来源: AIP