Open AccessRemoval of Methylene Blue by Activated Glass Foams with TiO2 in Dark and Simulated Solar Light
Author(s) -
Simona Rus,
S. Novaconi,
Paulina Vlăzan,
Mădălina Ivanovici
Publication year - 2019
Publication title -
analele universităţii de vest din timişoara. seria ştiinţe fizice/annals of west univesity of timişoara. physics series
Language(s) - English
Resource type - Journals
eISSN - 2784-1057
pISSN - 1224-9718
DOI - 10.2478/awutp-2019-0003
Subject(s) - oscillation (cell signaling) , germanium , diffusion , materials science , current (fluid) , bipolar junction transistor , optoelectronics , silicon , energy balance , energy (signal processing) , transistor , electrical engineering , physics , chemistry , thermodynamics , voltage , engineering , biochemistry , quantum mechanics
The effect of germanium trapezoidal profile shape on the direct current (DC) current gain (βF), cut-off frequency (fT) and maximum oscillation frequency (fMAX) of silicon-germanium (SiGe) hetero-junction bipolar transistors (HBTs) has been investigated. The energy balance (EB), hydrodynamic (HD) and drift-diffusion (DD) physical transport models in SILVACO technology computer aided design (T-CAD) simulator were used. It was found that the current gain values using energy balance model are higher than hydrodynamic and much higher than those corresponding to drift-diffusion. Moreover, decreasing the germanium gradient slope towards the collector side of the base enhances the maximum oscillation frequencies using HD and EB models whilst, they remain stable for DD model.