Before the nano era, electron field emission technological development was mainly associated with microtip field emitter arrays (FEAs), with further efforts to discover and develop other cold cathode materials for improved and more reliable performance. However, it was proving to be difficult in microtechnology to develop such FEA over a large area uniformly using a very manufacture-friendly process, thus making it cost-effective. Also, due to the higher work function of the materials used, the operating voltage for the sets of FEAs of microtips was rather high (50–100 V); thus, the power consumption is relatively high, and also it increases the probability of destruction of tips by ion bombardment and surface diffusion. These FEAs are highly vulnerable to environmental contamination and thus exhibit relatively stable behavior.