We report on the zinc oxide (ZnO) thin films obtained by the atomic layer deposition (ALD) method using diethyl zinc and water precursors, which allowed us to lower deposition temperature to below $200°\text{C}$ . The so-obtained “as grown” ZnO layers are polycrystalline and show excitonic photoluminescence (PL) at room temperature, even if the deposition temperature was lowered down to $100°\text{C}$ . Defect-related PL bands are of low intensity and are absent for layers grown at $140-200°\text{C}$ . This is evidence that extremely low temperature growth by ALD can result in high quality ZnO thin films with inefficient nonradiative decay channels and with thermodynamically blocked self-compensation processes.

We demonstrate that, even in unstrained GaN quantum wells with AlGaN barriers, there exist giant electric fields as high as 1.5 MV/cm. These fields, resulting from the interplay of the piezoelectric and spontaneous polarizations in the well and barrier layers due to Fermi level alignment, induce large redshifts of the photoluminescence energy position and dramatically increase the carrier lifetime as the quantum well thickness increases.

We report on zinc oxide thin films grown by atomic layer deposition at a low temperature, which is compatible with a low thermal budget required for some novel electronic devices. By selecting appropriate precursors and process parameters, we were able to obtain films with controllable electrical parameters, from heavily $n$ -type to the resistive ones. Optimization of the growth process together with the low temperature deposition led to ZnO thin films, in which no defect-related photoluminescence bands are observed. Such films show anticorrelation between mobility and free-electron concentration, which indicates that low $n$ electron concentration is a result of lower number of defects rather than the self-compensation effect.

We report on the electrical properties of thin film transistors based on zinc oxide (ZnO) layers grown by low temperature $(100–170°\mathrm{C})$ atomic layer deposition. As evidenced through Hall effect measurements, a drastic decrease of the carrier concentration occurred for ZnO films grown at $100°\mathrm{C}$ . Time of flight–secondary ions mass spectroscopy analysis revealed that this decrease is associated with an increase of the hydroxide groups in the ZnO layer which suppressed oxygen vacancy formation. Transistors fabricated from ZnO films grown at $100°\mathrm{C}$ exhibit a high $I_{\text{on}}∕I_{\text{off}}$ ratio $(\sim {10}^7)$ and an encouraging intrinsic channel mobility $(\sim 1{\mathrm{cm}}^2∕\mathrm{V}\mathrm{s})$ .