Observation of very high peak-to-valley current ratio (/spl ges/9.4) in amorphous silicon/silicon-carbide double barrier structure with barrier enhancement layer

A negative differential resistance current/voltage (I/V) curve with a very high peak-to-valley current (PTV) ratio (/spl ges/9.4) has been obtained in the a-Si:H/a-SiC:H double barrier structure with added amorphous silicon barrier enhancement layers. Although similar phenomena have been reported in the crystalline AlGaAs/GaAs double barrier diodes, the effect of the added barrier enhancement layers on the PTV ratio is not so significant as the amorphous silicon. A primary model is proposed to explain this anomalous result. Based on the model, the parameters to lower the leakage current and enhance the resonant tunneling current are suggested.<
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