Homogenization of the Observatoire de Haute Provence ECC ozonesonde data record: comparison with lidar and satellite observations

The Observatoire de Haute Provence (OHP) weekly Electrochemical Concentration Cell (ECC) ozonesonde data have been homogenized for the time period 1991–2020 according to the recommendations of the Ozonesonde Data Quality Assessment (O3S-DQA) panel. The assessment of the ECC homogenization benefit has been carried out using comparisons with ground based instruments also measuring ozone at the same station (lidar, surface measurements) and with collocated satellite observations of the O3 vertical profile by Microwave Limb Sounder (MLS). The major differences between uncorrected and homogenized ECC are related to a change of ozonesonde type in 1997, removal of the pressure dependency of the ECC background current and correction of internal ozonesonde temperature. The 3–4 ppbv positive bias between ECC and lidar in the troposphere is corrected with the homogenization. The ECC 30-years trends of the seasonally adjusted ozone concentrations are also significantly improved both in the troposphere and the stratosphere when the ECC concentrations are homogenized, as shown by the ECC/lidar or ECC/surface ozone trend comparisons. A −0.29 % per year negative trend of the normalization factor (NT) calculated using independent measurements of the total ozone column (TOC) at OHP disappears after homogenization of the ECC. There is however a remaining −5 % negative bias in the TOC which is likely related to an underestimate of the ECC concentrations in the stratosphere above 50 hPa as shown by direct comparison with the OHP lidar and MLS. The reason for this bias is still unclear, but a possible explanation might be related to freezing or evaporation of the sonde solution in the stratosphere. Both the comparisons with lidar and satellite observations suggest that homogenization increases the negative bias of the ECC up to 10 % above 28 km.

Transparent Flexible IGZO Thin Film Transistors Fabricated at Room Temperature

Flexible and fully transparent thin film transistors (TFT) were fabricated via room temperature processes. The fabricated TFT on the PEN exhibited excellent performance, including a saturation mobility (μsat) of 7.9 cm2/V·s, an Ion/Ioff ratio of 4.58 × 106, a subthreshold swing (SS) of 0.248 V/dec, a transparency of 87.8% at 550 nm, as well as relatively good stability under negative bias stress (NBS) and bending stress, which shows great potential in smart, portable flexible display, and wearable device applications.

Investigation of degradation mechanism after negative bias temperature stress in Si/SiGe channel metal-oxide-semiconductor capacitors induced by hydrogen diffusion

In this research, based on I-V and C-V measurement at different temperatures, the interface defect density in the device with the Si/SiGe channel was discussed. In addition, negative bias temperature instability (NBTI) is also studied. In previous research, most of the flat-band voltage (VFB) shifts during NBTI stress was attributed to hole injection. In this article, however, the release of atomic hydrogen from the Si–H bonds at the SiOV2/Si interface and at the SiGe interface produces a fixed oxide charge, which causes VFB shifts which vary with material.

Deposition of a titanium carbonitride coating by magnetron sputtering on a substrate with a potential voltage

Titanium carbonitride (TiCN) is of high relevance in the field of creating wear-resistant protective coatings in order to ensure maximum wear resistance and service life of parts of friction units. Titanium carbonitride coatings were obtained by magnetron sputtering at various bias substrate in the range from 0 to -130 V with a step of 10 V. The effect of the bias substrate on the deposition rate, phase and elemental composition, and the friction coefficient of the obtained coatings was investigated. As a result of the obtained dependences, the most optimal mode of deposition by the method of reactive magnetron sputtering with a negative bias voltage on the substrate was determined.