Temperature Dependence Of Conduction Mechanism Research Articles

Dielectric properties, conductivity and Li+ ion motion in LiPON thin films

LiPON films are prepared by Radio Frequency sputtering on 200 mm silicon wafers. LiPON elemental composition is investigated by RBS and NRA. Ionic conductivity is measured by impedance spectroscopy and electronic conductivity from Isothermal Transient Ionic Current (ITIC) in the temperature range 80 K–380 K on MIM cells. The ionic and electronic conductivities at room temperature are 1.2 × 10− 6 S/cm and 8 × 10− 14 S/cm respectively. Charge carrier concentration, mobility and Li ion diffusion coefficient are calculated. Temperature dependence of conduction mechanism in LiPON is described.

Structure and temperature dependence of conduction mechanisms in hot wall deposited CuInSe 2 thin films and effect of back contact layer in CuInSe 2 based solar cells

Copper indium diselenide (CuInSe 2) was prepared by direct reaction of high purity elemental Copper, Indium and Selenium. CuInSe 2 thin films were prepared on well-cleaned glass substrates by a hot wall deposition technique. The X-ray diffraction studies revealed that all the deposited films are poly crystalline in nature, single phase and exhibit chalcopyrite structure. The crystallites were found to have a preferred orientation along the (112) direction. Structural parameters of CuInSe 2 thin films coated with higher substrate temperatures were also studied. As the substrate temperature increases the grain size increases. The resistivity is found to decrease with increase in temperature. Two types of conduction mechanisms are present in the hot wall deposited CuInSe 2 films. In the temperature region below 215 K the conduction is due to a variable range hopping mechanism and in the temperature region above 215 K the conduction is due to a thermally activated process. It is observed that the solar cell with molybdenum as back contact has low series resistance ( R s), high shunt resistance ( R sh) and large fill factor (FF) when compared with CuInSe 2 based solar cells with other back contact material layers.

Temperature Dependence of the Current Conduction Mechanisms in Sm2O3 Thin Films

Metal-oxide-semiconductor capacitors with dielectric film were fabricated and the temperature dependence of the conduction mechanisms was studied. The films were deposited by radio frequency magnetron sputtering. The thickness of was . The dielectric permittivity and the equivalent oxide thickness of capacitors with film were 15.0 and , respectively. The X-ray photoelectron spectroscopy analysis showed a silicate interfacial layer formed between and Si. When the aluminum electrode was biased positive, the dominant conduction mechanism was Schottky emission in the temperature range and at an electrical field of . In the temperature range , the dominant conduction mechanism was most likely space-charge-limited conduction. When the aluminum electrode was biased negative, the dominant conduction mechanism in the temperature range from and at an electrical field from was Schottky emission. At and with the electrical field above , the conduction mechanism was Fowler—Nordheim (F–N) tunneling. The electron barrier height and the effective electronic mass calculated from Schottky emission and F–N tunneling were and , respectively.

Temperature dependence of conduction mechanism of ZnO and Co-doped ZnO thin films

ZnO and Co-doped ZnO thin films have been deposited on the sapphire substrate by ultrasonic assisted chemical vapor deposition technique. The films were annealed in vacuum at 450 °C. All the films were highly c-axis orientated and contained no impurity phase. The temperature dependence of the electrical conductivity has been measured in order to identify the dominant conduction mechanism. In the higher temperature region the dominance of thermally activated band conduction was observed whereas in the low temperature region the hopping conduction was found to dominate. The hopping conduction mechanism in the lower temperature range in the film was Mott's Variable Range Hopping and not the Nearest Neighbor Hopping. The temperature region, where hopping conduction was dominant found to increase by Co doping in ZnO film. The localization length was found to be larger in the Co-doped ZnO film.

Electronic transport properties of NiPS3.

The temperature dependence of conduction mechanisms in pure ${\mathrm{NiPS}}_{3}$ has been investigated by means of conductivity, photoconductivity, and thermopower measurements. Evidence for a p-type conduction has been found from the thermoelectric power data. The observed activated behaviors of thermopower, dark conductivities, and photoconductivities have allowed us to deduce more detailed information about the distribution of the electronic density of states in the energy-gap region. The results, fitted by assuming a single conduction path through extended-band states, have been interpreted in terms of an energy-band scheme based on a model regarding as insignificant the contribution of the 3d transition-metal states in bond.