화학공학소재연구정보센터
Journal of Crystal Growth, Vol.507, 10-15, 2019
Ternary Pb1-xCdxSe films grown by molecular beam epitaxy on GaAs/ZnTe hybrid substrates
Thin epitaxial Pb1-xCdxSe 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 Pb1-xCdxSe 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 Pb1-xCdxSe 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 Pb1-xCdxSe 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 x 10(18) cm(-3) in the pure PbSe film down to 3 x 10(16) cm(-3) in the film containing x = 0.052 of Cd. The reduction of the hole concentration by two orders of magnitude makes the Pb1-xCdxSe films very attractive for infrared detector applications. Simple photoresistors made of Pb1-xCdxSe films exhibit sensitivity to the infrared radiation up to the room temperature.