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The compositional profile of the interface between plasma-deposited amorphous silicon (a-Si[ATOTHER]@B:[/ATOTHER]H) and silicon nitride (a-SiNx:H) thin films has been examined using high depth resolution Rutherford backscattering spectrometry. We have optimized the grazing exit angle geometry of the measurement using a model calculation which predicts a ∼20 Å interface depth resolution. The fundamental noise sources considered in the calculation are the energy straggling and angular divergence of ions traversing the target, detector noise, and geometrical effects. Experimentally, the major compositional change for both Si and N is found to take place within the interface depth resolution which is 18 Å. However, we find a tail of ∼3 at. % nitrogen extending through a 50-Å a-Si:H layer deposited on top of a-SiNx:H. Such a tail is not expected for the reverse order of layer deposition. The compositional asymmetry depending on the order of deposition is presumably associated with the reported asymmetry in the charge density at interfaces. The nitrogen contamination further implies that most a-Si:H/a-SiNx:H quantum well structures are in fact based on nitrogen alloyed a-Si:H layers. [ABSTRACT FROM AUTHOR]

The effects of a graded composition layer at the amorphous silicon/nitride interface are studied using transient photoconductivity. The graded layer causes a large increase in the density of slow states (electrons trapped within the nitride), but does not influence the fast interface states. The kinetics of trapping and release are measured and a model of field assisted hopping and thermal excitation is proposed. The different origins of slow and fast states are also discussed. [ABSTRACT FROM AUTHOR]

We have investigated the time and intensity dependence of the creation process for light-induced metastable defects (Staebler-Wronski effect) in hydrogenated amorphous silicon (a-Si:H). The observed changes in electron spin resonance spin density (dangling bonds) and photoconductivity are consistent with a model which explains the Staebler-Wronski effect as a self-limiting process intrinsic to a-Si:H. A possible microscopic mechanism based on the nonradiative recombination of band tail carriers is discussed. [ABSTRACT FROM AUTHOR]

In this letter we describe the operation of a new high-speed, high-gain amorphous silicon sensor. The device gain originates from the photoconductive properties of amorphous silicon but good light to dark sensitivity is obtained by suppressing the sensor dark current by means of a lightly p-type barrier layer. Optical gains in excess of 100 have been achieved with response times of approximately 200 μs. [ABSTRACT FROM AUTHOR]

Replies to comments on the authors' article on a kinetics model proposed for the electron-hole recombination in amorphous semiconductors. Multiphonon cascade; Optical energy concentration.