화학공학소재연구정보센터
Thin Solid Films, Vol.461, No.2, 256-265, 2004
PbTe films grown by hot wall epitaxy on sapphire substrates
A 'hot wall epitaxy' is applied to grow PbTe thin films on sapphire substrates with BaF2 buffer layer deposited by molecular beam epitaxy (MBE). The microstructural and strain state characteristics of PbTe layer were examined with high resolution X-ray diffraction techniques. The epilayer is composed of two (111)PbTe parallel to (0001)Al2O3 epitaxially oriented domain variants. The domains are azimuthally rotated and their interfacial directions relative to the substrate are [01 (1) over bar ]PbTe parallel to [2 (1) over bar(1) over bar0]Al2O3 and [(1) over bar5 (4) over bar ]PbTe parallel to [2 (1) over bar(1) over bar0]Al2O3, respectively. Another possible alignment of the domain variant corresponds to [3 (1) over bar(2) over bar ]PbTe parallel to [3 (1) over bar(2) over bar0]Al2O3 orientation. The strain state analysis of PbTe layer points to its relaxation via domain formation and high dislocation density generation in the lattice. Despite the domains formation the measured mobility of electron carriers is approximately 1600 cm(2)/V s and 30000 cm(2)/V s at 300 K and 77 K, respectively. The theoretical analysis of the measured electrical properties indicates that the scattering by acoustic and optical phonons is the factor affecting the conduction process. (C) 2004 Elsevier B.V. All rights reserved.