Modeling of radiation damage recovery in particle detectors based on GaN

Simulations of Operation Dynamics of Different Type GaN Particle Sensors

“…The simplified models [ 17 , 18 , 19 , 20 ], based on Ramo’s expression for the drift current, are attractive as they provide a simple analytical description of the detector signals. However, the analytical expressions can only be obtained for the simplest approximations.…”

“…The sign (polarity) of the injected charge and a direction of the drift velocity vector are also included. The surface charge ( σ , q ) vectors, determined commonly [ 17 , 18 , 19 , 20 ] as a discontinuity of electrostatic displacement vectors D , for instance in Figure 1 : − q e = ( D 2 − D 3 ) = n e εε 0 E qe are initially considered. Then, the scalar equations for an instantaneous field distribution are analyzed.…”

“…Variations of the acting electric field E (ψ( t )) in time and as a function of dimensionless position ψ( t ) can be determined using the dynamic approach [ 17 , 18 , 19 , 20 ].…”

“…Competition of recombination (τ) and multiplication m = M ( t , n ) in Equation (112) is accounted for in modification of drift velocity within each segment by a sum of quantities (−τ tr ,λ ii /τ) + M (τ tr ,λ ii ,1) ≥ 1 . Additionally, dependence of acting field dependence on the amount of drifting charge ( eR η e <M ( x ) >| λ ii ) with approach of x (or ( d − x )) to electrode is included, according to dynamic model [ 17 , 18 , 19 , 20 ], in other words, shortening of τ Mq with increase of the amount of drifting charge is taken into account.…”

“…The vector origin of the employed quantities of a surface charge domain, of an electric field and of charge motion velocity have always been kept in mind, while the scalar relations are mainly represented. Additionally, the charge multiplication processes and transients of detector current have been analyzed using this dynamic approach [ 17 , 18 , 19 , 20 ] based on the Shockley-Ramo theorem [ 8 , 9 ]. To simplify analysis, application of the dynamic approach is confined to the capacitor type detector based on thin MOCVD grown GaN epi-layers.…”