Photonic and electronic properties exist inherently in ferroelectric barium titanate (BaTiO₃); severe luminescence quenching also exists due to the insufficient confinement of excitons. In this sense, high optical emission can only be achieved by its chemical and structural modification. Thin BaTiO₃ and Er:BaTiO₃ films were grown by the spin coating method on a glass substrate at room temperature. Self-trapping of excitons in the thin BaTiO₃ film and its structural modification due to the doping with Er³⁺ ions (Er:BaTiO₃) are verified using scanning confocal fluorescence microscopy (SCFM), where self-trapping excitons never occured in its pure state. By thermal treatment and doping (BaTiO₃ and Er:BaTiO₃) we obtained localization of the excitons, which would further induce lattice strain around the surface defects, to accommodate the self-trapped excitons. With such a self-trapped state, the structure of BaTiO₃ generates broadband emission of several overlapping bands between 1.95 and 2.65 eV at room temperature, while the structure Er:BaTiO₃ showed defined emission bands at 2.24 and 2.35 eV, with very weak contributions of the emission due to the self-trapping state. The influence of the variation of the excitation wavelength using 1PE and 2PE on the emission bands of BaTiO₃ and Er:BaTiO₃ is also investigated. The results of enhanced emission bands suggest a clear dependence of the emission intensity on the excitation energy, where a ∼3 fold enhancement in emission has been demonstrated under Er³⁺ (1.55 eV) excitation, which can be attributed to effective energy transfer between the Er³⁺ ions. As a result, it is concluded that the developed BaTiO₃ and Er:BaTiO₃ can pave the way for future photonic devices.

Scaling of surface fluctuations of polycrystalline CdTe/Si(100) films grown by hot-wall epitaxy are studied. The growth exponent of surface roughness and the dynamic exponent of the autocorrelation function in the mound growth regime agree with the values of the Kardar-Parisi-Zhang (KPZ) class. The scaled distributions of heights, local roughness, and extremal heights show remarkable collapse with those of the KPZ class, giving an experimental observation of KPZ distributions in $2+1$ dimensions. Deviations from KPZ values in the long-time estimates of dynamic and roughness exponents are explained by spurious effects of multipeaked coalescing mounds and by effects of grain shapes. Thus, this scheme for investigating universality classes of growing films advances over the simple comparison of scaling exponents.

We investigate the doping behavior of ZnSe/ZnTe short period superlattices. p-type doping is achieved with a dc nitrogen plasma source, n-type doping with chlorine from a ZnCl2 Knudsen source. Even a small Te content has a strong positive effect on p doping: Doping levels in the upper 1019 cm−3 range are achieved, and ohmic contacts can be obtained even for low carrier concentrations. The data are in excellent agreement with a theory based on the amphoteric native defect model. The opposite is valid for n doping: At Te concentrations above 20% electron concentrations are below 1016 cm−3. As a possible way to get both good n- and p-type doping at the same lattice constant we propose the use of the quaternary compound Zn(1−y)Mg(y)Se(1−x)Te(x).