Observation of plasma sheath modulation in the plasma bipolar junction transistor

Summary form only given. The coupling of a low-temperature, weakly-ionized gas phase plasma with the electron-hole (e^--h⁺) plasma of a semiconductor was demonstrated in 2010 by Wagner, Tchertchian and Eden in the form of the plasma bipolar junction transistor (PBJT). By specifying the densities of electrons in both the conduction band and the valence band, the electronic properties of the surface of the semiconductor base (collector cathode) can be controlled. The structure of this device presents an opportunity for studying the underlying physics occurring at the interface between two genres of plasmas, and allows the investigation of the impact of a pn junction on the effective secondary electron emission coefficient at the surface of the PBJT´s base. In this work, we report the modulation of the plasma sheath in the PBJT for input voltages of less than one volt. The degree of modulation implies a ~360% change in the effective secondary electron emission coefficient of the cathode surface, with an associated change in the electron density of the gas-phase plasma. This type of control over the plasma density with the application of a single volt is not only unprecedented, but suggests potential applications ranging from plasma chemistry and materials processing to lighting and display technologies.In this work, we report the modulation of the plasma sheath in the PBJT for input voltages of less than one volt. The degree of modulation implies a -360% change in the effective secondary electron emission coefficient of the cathode surface, with an associated change in the electron density of the gas-phase plasma. This type of control over the plasma density with the application of a single volt is not only unprecedented, but suggests potential applications ranging from plasma chemistry and materials processing to lighting and display technologies.