Silicon nanowires: the promoter of performance improvement of microplasma in a microcavity array device.

A microcavity array device decorated by silicon nanowires (SiNWs) is fabricated and the discharge property improvement is investigated. The array device can be operated stably from several kPa to atmospheric pressure of argon, powered by a 20 kHz bipolar nanosecond pulse source. Profiting by electron emission from SiNWs, the microplasma discharge dynamics and emission properties are significantly enhanced. Experimental results manifest that the instantaneous total current of the device decorated by SiNWs is up to ∼20% higher than that of the device without SiNWs and the mean current is increased by ∼12.5% compared with the conventional device (without SiNWs), and the ignition voltage decreased by ∼24%. The setup time is less than 90 ns before the device is fully ignited, and emission intensity enhanced by over 60% compared with the conventional plain surface device. Moreover, calculated by Lissajous figures, the discharge power of proposed device is higher than that of the traditional device with increment of ∼26%, and the impact of SiNWs on microdischarge processes is analyzed. The mechanism of the microplasma property enhancement is discussed through introducing the electric field enhancement effect at SiNWs cap and initial seed electrons emitted from SiNWs. This work combines the characteristic advantages of SiNWs with microcavity gas discharge to achieve the performance improvement of microplasma, and the results reported here has profound impacts on improving microplasma discharge properties and implies potential significance in promoting the performance of plasma applications. [ABSTRACT FROM AUTHOR]