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Mesoporous TiO(2) with a large specific surface area (~150 m(2) g(-1)) is the most successful material in dye-sensitized solar cells so far; however, its inferior charge mobility is a major efficiency limiter. This paper demonstrates that random nanowires of Ni-doped TiO(2) (Ni:TiO(2)) have a dramatic influence on the particulate and charge transport properties. Nanowires (dia ~60 nm) of Ni:TiO(2) with a specific surface area of ~80 m(2) g(-1) were developed by an electrospinning technique. The band gap of the Ni:TiO(2) shifted to the visible region upon doping of 5 at% Ni atoms. The Mott-Schottky analysis shows that the flat band potential of Ni:TiO(2) shifts to a more negative value than the undoped samples. The electrochemical impedance spectroscopic measurements showed that the Ni:TiO(2) offer lower charge transport resistance, higher charge recombination resistance, and enhanced electron lifetime compared to the undoped samples. The dye-sensitized solar cells fabricated using the Ni:TiO(2) nanowires showed an enhanced photoconversion efficiency and short-circuit current density compared to the undoped analogue. The transient photocurrent measurements showed that the Ni:TiO(2) has improved charge mobility compared with TiO(2) and is several orders of magnitude higher compared to the P25 particles.

Abstract-An ultrafast on-the-fly technique is developed to study linear drain current (I DLIN ) degradation in plasma and thermal oxynitride p-MOSFETs during negative-bias temperature instability (NBTI) stress. The technique enhances the measurement resolution ("time-zero" delay) down to 1 μs and helps to identify several key differences in NBTI behavior between plasma and thermal films. The impact of the time-zero delay on time, temperature, and bias dependence of NBTI is studied, and its influence on extrapolated safe-operating overdrive condition is analyzed. It is shown that plasma-nitrided films, in spite of having higher N density, are less susceptible to NBTI than their thermal counterparts.Index Terms-Field acceleration, negative-bias temperature instability (NBTI), plasma oxynitride, p-MOSFET, safe-operating voltage, temperature activation, thermal oxynitride, time exponents.

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Negative Bias Temperature Instability (NBTI) is studied in Silicon Oxynitride (SiON) p-MOSFETs using a recently developed UltraFast On-The-Fly linear drain current (UF-OTF I DLIN ) method. It is shown that both stress and recovery phases of NBTI are strongly influenced by SiON gate insulator process. Gate insulator nitrogen (N) spatial distribution is shown to impact interface trap generation (∆N IT ) and hole trapping (∆N h ) components of overall threshold voltage shift (∆V T ). A simple, self consistent method is proposed to isolate ∆N IT and ∆N h . It is shown that the time dynamics of stress and recovery phases are strongly correlated, at short time governed by trapping and detrapping of holes, and at long time by generation and passivation of interface traps.