The current-voltage characteristics and the low-frequency noise spectra of p-type Si–Porous Si–Al diode like structures were investigated. Over 1 V forward biases a reasonable fit was obtained in the Fowler-Nordheim plot. Any attempts of accurately fitting the I-V characteristic by other known transport mechanisms failed. At lower biases, however, an additional current-component appears which shows a saturating character. This current component is ascribed to trap-assisted tunneling. The measured noise spectra show 1/f character; however the magnitude of the noise shows saturation with increasing biases instead of the usual case, where the noise power scales with I~2, or V~2. This finding is interpreted by a model of two parallel current paths. The noise arising from the smaller and saturating current determines the noise performance of the whole device.
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