Oxide Thin Film Heterostructures on Large Area, with Flexible Doping, Low Dislocation Density, and Abrupt Interfaces: Grown by Pulsed Laser Deposition

Figure 28

TEM bright field (11.0) cross sections of homoepitaxial undoped ZnO film E1289 taken with two different g-vectors (left), taken by Wagner (see [54]). The few dislocations for 𝑔-vector in c-direction are out of contrast for𝑔=[−11.0], therefore their Burgers vectors are of c-type. The film thickness is 893±5 nm, as determined from the intensity oscillations in the HR-XRD 2Θ−ω scan (not shown here). The right inset (provided by W. Mader, Bonn) shows for comparison a heteroepitaxial PLD ZnO film on c-plane sapphire E435 with much higher dislocation density, in particular near the interface.