Amorphous silicon thin films, fabricated by thermal conversion of neopentasilane, were used to passivate crystalline silicon surfaces. The conversion is investigated using X-ray and constant-final-state-yield photoelectron spectroscopy, and minority charge carrier lifetime spectroscopy. Liquid processed amorphous silicon exhibits high Urbach energies from 90 to 120 meV and 200 meV lower optical...

Recent progress in surface passivation technology and wafer pretreatment already resulted significant improvements the achievable minority charge carrier lifetime of crystalline silicon. Herein, this is further exemplified by studying on lowly doped silicon wafers passivated poly-Si. To ensure credible measurements multiple measurement techniques are compared good agreement between investigated...

An effective defect passivation route has been demonstrated in the rapidly growing Cu2ZnSn(S,Se)4 (CZTSSe) solar cell device system by using Cu2ZnSnS4:Na (CZTS:Na) nanocrystals precursors. CZTS:Na nanocrystals are obtained by sequentially preparing CZTS nanocrystals and surface decorating of Na species, while retaining the kesterite CZTS phase. The exclusive surface presence of amorphous Na spe...

This paper describes a Spicexompatible circuit reliability simulation model of submicron LDD MOS devices. It incorporates an accurate hot carrier model of the degraded MOSFEX characteristics under long term operations, which includes a drain current model and a substrate current model. The drain current reduction is modeled as mobility degradation due to interface states enhanced scattering. Th...

We report evidence of nonequilibrium hot carrier extraction from graphene by gate-dependent photocurrent study. Scanning photocurrent excited by femtosecond pulse laser shows unusual gate dependence compared with continuous wave (CW) laser excitation. Power dependence studies further confirm that the photocarriers extracted at the metal/graphene contact are nonequilibrium hot carriers. Hot carr...

Nonlinear absorption at 1.064 and 1.535 microm wavelengths by two photon and free carrier absorption processes in undoped and Fe doped InP has been investigated. Using picosecond and nanosecond duration lasers, a self-consistent set of the two photon and free carrier absorption coefficients are experimentally obtained through nonlinear transmission measurements for the first time. Reduced carri...

The orthogonality between sub-carriers in OFDM systems is disrupted by offsets between the carrier frequencies in the transmitter and receiver as well as by the so-called IQ mismatch in the mixers. When treated separately, effective algorithms exist for estimation and compensation of frequency offset as well as IQ imbalance. However, with both effects present, such algorithms do not lead to use...

In recent years, visible light communication (VLC) technology has attracted intensive attention due to its huge potential in superior processing ability and fast data transmission. The transmission rate relies on the modulation bandwidth, which is predominantly determined by the minority-carrier lifetime in III-group nitride semiconductors. In this paper, the carrier dynamic process under a str...

in the current engineering practices, buildings are commonly designed for an effective lifetime of 50 years. this lifetime can increase the cost of buildings with short lifetimes and can reduce the safety level of buildings with large lifetimes. in this paper, a “service-life factor” has been defined. applying this factor into the nominal values of live, earthquake, wind, and snow loads, the ef...