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In this study, the effect of annealing ambient on SnO 2 thin film transistors (TFTs) is presented. Phase pure SnO 2 films have been deposited using solution processed spin coating technique with SnCl 2 as the precursor material. The films are annealed at 500 °C for 1 h in different annealing ambient conditions with varying N 2 :O 2 ratio. Top gate, bottom contact TFTs have been fabricated with SnO 2 as the channel layer, silicon as the gate, silicon dioxide as the dielectric and gold as the contact material. XRD patterns reveal the amorphous nature of films. AFM image shows that the spin coated films are pin-hole free with extremely smooth surface morphology. PL and XPS measurements reveal that with increase in N 2 % during annealing, the defects in the films increase. However, with increase in nitrogen concentration, the device performance improves, the threshold voltage shifts towards lower values and mobility increases, but very high N 2 % is not suitable for device operation, a 70% N 2 + 30% O 2 annealing ambient is found to be suitable with devices showing saturation mobility of 0.23 cm 2 V −1 s −1 and threshold voltage of 6.8 V and on/off ratio of 10 6 .

We report on the growth of ZnO nanostructures in different gas ambient (Ar and N 2 ) using pulsed laser deposition technique. Despite the similar growth temperature, use of N 2 ambient gas resulted in well-aligned nanorods with flat surface at the tip, whereas, nanorods grown with Ar ambient exhibited tapered tips. The Nanorods grown under N 2 ambient exhibited additional Raman modes corresponding to N induced zinc interstitials. The nanorods are c-axis oriented and highly epitaxial in nature. Photoluminescence spectroscopy reveals that the UV emission can be significantly enhanced by 10 times for the nanorods grown under Ar ambient. The enhanced UV emission is attributed to the reduction in polarization electric field along the c-axis. n -ZnO nanorods/p-Si heterojunction showed rectifying I–V characteristics with a turn of voltage of 3.4 V.

We demonstrate reversible p -type nature of pulsed laser deposited (P, N) codoped ZnO thin films using rapid thermal annealing process. As grown thin films exhibited change in conductivity from p to n -type over a span of 120 days. Non-annealed n -type thin films contain unintentional donor impurities such as hydrogen and carbon. X-ray photoelectron spectroscopy and Raman measurements conclusively show that hydrogen passivates nitrogen acceptors by forming N H complex. Carbon can be annealed out at 600 °C, whereas, the dissociation of N H complex takes place at 800 °C. The films revert its p -type nature at an annealing temperature of 800 °C.

In this paper we report the detailed analysis of the effect of in-situ annealing on the electrical properties of yttrium stabilized zirconium oxide (YSZ) thin films grown by pulsed laser deposition on silicon substrates. The optimized metal/YSZ/Si devices showed low leakage current, good dielectric strength and a breakdown field strength of 4.13 MV/cm. The magnitudes of flat band voltage, and interfacial charge density have been extracted from the capacitance-voltage (C-V) characteristics of the MOS structure. The C-V characteristics show a small hysteresis which indicates the presence of traps. The observed shift in the flat band voltage and hysteresis are explained with the help of X-ray photoelectron spectroscopy. From the XPS depth profile analysis of the samples it was found that as we go from the surface to the interface, oxygen concentration in the deposited film decreases, i.e. the oxide becomes zirconium rich. This has been correlated with the observed electrical properties.

We report on the growth of violet emitting p-type ZnO thin films, with phosphorous (P) and nitrogen (N) codoping, using pulsed laser deposition. XPS studies show that the phosphorous is substituted at Zn site, whereas nitrogen is substituted at oxygen site. Hall measurements confirmed the p-type nature in codoped ZnO thin films. I-V characteristics of the heterojunction formed by n-Si and P, N: ZnO showed rectifying nature. Strong violet emission in PL spectra is attributed to the formation of zinc vacancies. We propose a defect complex, (PZn-VZn-4NO), which acts as an effective acceptor in the P and N codoped ZnO. � 2015 Elsevier B.V.