Studies of field emission current from amorphous silicon deposited on a tungsten tip

Field electron emission from an amorphous silicon deposited tungsten tip has been studied. The current–voltage (I–V) characteristics corresponding to the as-deposited and annealed states of the emitter were recorded. These characteristics showed semiconducting behaviour. Field emission current fluctuations from the two states were recorded. As-deposited tip shows more spikes in low-field region and a mixture of spikes and steps at higher fields. Fast Fourier Transform analysis of the current signal shows Lorentzian-type of power spectrum which is indicative of bistable traps in a-Si : H. Total emission current level remained almost constant for the entire duration of recording.