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The electrical characteristics and reliability of Hf-In-Zn-O (HIZO) metal-oxide-semiconductor capacitors (MOSCAPs) with a microporous SiO2-based electric-double-layer (EDL) dielectric were investigated. Experimental results indicated that the HfO2 interlayer could effectively improve the interface quality, thus leading to reduced interface states, suppressed hysteresis and decreased gate leakage current. Improved performance was achieved for the HIZO MOSCAPs with HfO2/EDL stack gate dielectrics (HECAPs), such as a large capacitance density of 0.7μF/cm2, an interface state density of 5.7×1011 eV−1/cm2, a fixed charge density of 1.9×1012 cm−2, a hysteresis voltage of 230mV and a gate leakage current density of 3×10−6 A/cm2 at +1V. Moreover, enhanced reliability of the HECAPs was obtained with an elevated dielectric breakdown voltage of 4.8V and a small increase (< 15 %) of gate leakage after gate bias stressing at 2V for 3600s. [ABSTRACT FROM AUTHOR]

Abstract: Efficient organic solar cells (OSCs) based on regioregular of poly (3-hexylthiophene): fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester composites have been fabricated on fluorine-doped tin oxide coated glass substrates by using a sputtered indium oxide film as a hole-transporting layer (HTL). Optimized parameters for p-type In2O3 layer fabrication have been obtained through In2O3 layer sputtering temperature modulation. Based on this HTL, photovoltaic devices have been fabricated, and a power conversion efficiency up to 1.32% has been achieved. With the help of X-ray photoelectron spectroscopy and Hall-effect measurements, we conclude that the formation of In(OH)3/InOOH on the surface of In2O3 film could increase the electrical resistivity of films and affect the performance of OSC further. [Copyright &y& Elsevier]

Abstract: Efficient organic solar cells based on the blends of poly (3-hexylthiophene) (P3HT):fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) composites have been fabricated by using the sputtered amorphous chromium oxide (ACO) film on fluorine-doped tin oxide (FTO) coated glass substrates as a hole-transporting layer (HTL). Through ACO layer sputtering temperature, film thickness and oxygen flow ratio optimization, the highest power conversion efficiency of 3.28% of FTO/ACO/P3HT:PCBM/Al solar cells on glass has been achieved under AM1.5G 100mW/cm2 illumination. It is found that the device with 10nm thick ACO sputtered at 473K and oxygen flow ratio f(O2) (O2/O2 +Ar)=40% shows the best photovoltaic properties. The photovoltaic properties in these devices are discussed in terms of the band diagrams and series resistance of the devices, and characteristics of ACO HTL. It is concluded that ACO is a suitable alternative to poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) as a HTL. [Copyright &y& Elsevier]

Abstract: Polycrystalline p-type Cu x O films were deposited after the growth of HfO2 dielectric on Si substrate by pulsed laser deposition, and Cu x O metal-oxide-semiconductor (MOS) capacitors with HfO2/SiO2 stack gate dielectric were primarily fabricated and investigated. X-ray diffraction and X-ray photoelectron spectroscopy were applied to analyze crystalline structure and Cu+/Cu2+ ratios of Cu x O films respectively. SiO2 interlayer formed between the high-κ dielectric and substrate was estimated by the transmission electron microscope. Results of electrical characteristic measurement indicate that the permittivity of HfO2 is about 22, and the gate leakage current density of MOS capacitor with 11.3nm HfO2/SiO2 stack dielectrics is ∼10− 4 A/cm2. Results also show that the annealing in N2 can improve the quality of Cu x O/HfO2 interface and thus reduce the gate leakage density. [Copyright &y& Elsevier]

Using a highly conductive ZnO (ZnAl2O4) ceramic target, c axis-oriented and oxygen-deficient Al-doped ZnO (ZAO) thin films were prepared on glass sheet substrates by radio frequency (RF) planar magnetron sputtering. The structural, electrical and optical properties of the films (deposited at room temperature and annealed at different conditions) were characterized with various techniques. The experimental results show that the electrical resistivity of as-grown films can be decreased to 10−4 Ω cm level with post-deposition annealing at 400 °C for 2 h in a vacuum pressure of 10−5 torr. By increasing the annealing temperature, the oxygen vacancies and carrier concentration of ZAO thin film increase, and the absorption edge in the transmission spectra shifts toward the shorter wavelength side (blue shift). The oxygen vacancy plays an important role in the electrical conductivity. The more the oxygen vacancies exist in ZAO thin films, the higher the electrical conductivity will be. [Copyright &y& Elsevier]