Ternary Pb1−xCdxSe films grown by molecular beam epitaxy on GaAs/ZnTe hybrid substrates.

Highlights • The high quality monocrystalline Pb 1−x Cd x Se epitaxial films grown by MBE technique. • HRXRD analysis reveals that introduction of Cd atoms into the crystal lattice of PbSe decreases the lattice constant. • The energy gap of Pb 1−x Cd x Se films increases with the increasing Cd content. • The introduction of Cd atoms into the crystal lattice of PbSe significantly reduces hole concentration. Abstract Thin epitaxial Pb 1−x Cd x Se films with cadmium content x ≤ 0.36 have been grown by molecular beam epitaxy (MBE) on highly resistive, lattice matched (0 0 1) ZnTe/GaAs hybrid substrates. The High Resolution X-ray Diffraction (HRXRD) indicates that the films crystallize in the rock salt structure. Up to x = 0.12 the Pb 1−x Cd x Se films are (0 0 1) oriented and monocrystalline with negligible amount of other phases. The lattice constant of the films decreases proportionally to the Cd content. As evidenced by low-temperature photoluminescence (PL) the energy gap of Pb 1−x Cd x Se films increases with the increasing Cd content. The parameters of optical phonons and plasmons in the material are established by infrared reflectance measurements. The most interesting property of the Pb 1−x Cd x Se films is revealed by classical transport measurements. The alloying of PbSe with CdSe reduces the hole concentration in the material from a typical value of 3 × 1018 cm−3 in the pure PbSe film down to 3 × 1016 cm−3 in the film containing x = 0.052 of Cd. The reduction of the hole concentration by two orders of magnitude makes the Pb 1−x Cd x Se films very attractive for infrared detector applications. Simple photoresistors made of Pb 1−x Cd x Se films exhibit sensitivity to the infrared radiation up to the room temperature. [ABSTRACT FROM AUTHOR]