Epitaxial Growth and Optical Properties of PbTe/CdTe Semiconductor Heterostructures

Abstract

Growth optimization, optical and structural properties of PbTe/CdTe multilayers grown by molecular beam epitaxy on GaAs (001) as well as on BaF2 (111) substrates is reported. An intense photoluminescence in the mid--infrared region is observed from PbTe quantum wells excited with 1.17 eV pulsed YAG:Nd laser. The energy of the emission peak shows blue shift with decreasing PbTe well width and has a positive temperature coefficient. The influence of thermal annealing on photoluminescence spectra of PbTe/CdTe multilayers grown on BaF 2 substrate is discussed.

Nanoscale morphology of multilayer PbTe/CdTe heterostructures and its effect on photoluminescence properties

“…It is interesting to note, that the 230 °C structure, which exhibits the 2D SL-like order does not show any room temperature PL signal. The lack of PL signal in the 2D structure confirms previous observation that the intensity of the PL signal strongly depends on the thickness of the PbTe QW and for wells thinner than about 10 nm the PL disappears at elevated temperatures [16]. The temperature quenching of the PL signal of the 230 °C structure is caused by the low binding energy of photoexcited holes in thin 2D PbTe layers.…”

“…2D PbTe/CdTe nanostructures-quantum wells (QWs) and SLs-have attracted less attention so far [15,16]. Despite the crystal-structure mismatch an intense emission from QWs was observed in the mid-infrared region.…”

Optical and structural properties of Pb1−xEuxTe/CdTe//GaAs (001) heterostructures grown by MBE

“…It is important to achieve good optical confinement, in particular in designing efficient Bragg mirrors [4]. Strong electronic carrier confinement and small Auger recombination rate, characteristic for IV-VI semiconductors, result in strong mid-infrared photoluminescence observed in PbTe/CdTe heterostructures even above room temperature [5][6][7][8][9]. These properties could be very useful for advanced infrared optoelectronic devices operating at room temperature.…”