Comparative Study of Current Transients in HPHT and CVD Diamond Capacitor-Sensors. (1st January 2016)

• Record Type: Journal Article
• Authors: Gaubas, E.; Ceponis, T.; Meskauskaite, D.; Simoen, E.
• Is Part Of: ECS journal of solid state science and technology. Volume 5:Number 4(2016)
• Page Start: P3101
• Page End: P3107
• Publication Date: 2016-01-01
• Subjects: Charge induction -- Diamond Detectors -- Materials for solid-state detectors -- Radiation-hard detectors; Solid state chemistry -- Periodicals; Electronics -- Materials -- Periodicals; Electrochemistry -- Periodicals; 541.0421
• DOI: 10.1149/2.0191604jss
• Languages: English
• ISSNs: 2162-8777

Abstract

Abstract : Capacitor type sensors fabricated on CVD and HPHT diamond have been examined by combining measurements of the capacitance pulsed charging current transients, to reveal charge collection parameters, and sensor transient currents profiled using regimes of the perpendicular and parallel injection of excess carrier domains, in order to determine the predominant phenomena in formation of sensor signals. The recorded sensor current transients have been fitted using a simulated current pulse shape and their changes dependent on injection regime, based on the developed dynamic models derived from Shockley-Ramo's theorem. The surface charge formation mechanisms, polarization effects in the range of low bias voltage, the screening effects ascribed to dynamics of extraction of the injected bulk excess carrier packets have been discriminated and explained. The electron and hole mobility values of μe = 4000 cm 2 /Vs and μh = 3800 cm 2 /Vs, respectively, in CVD diamond have been evaluated through current transient profiling dependent on injection location. The close values of Da = 90 ± 10 cm 2 /s for the coefficient of carrier ambipolar diffusion independently measured by pulsed techniques of capacitor charging and sensor signal variations in the same detector structures corroborate the developed models for consideration of sensor signals under manifestation of various effects.