First observation of the charge carrier density related gain reduction mechanism in LGADs with the Two Photon Absorption-Transient Current Technique

The Low Gain Avalanche Detector (LGAD) technology is very promising for silicon timing detectors and currently heavily researched. Recent studies show that the gain of LGADs highly depends on charge carrier density inside layer. To study related reduction, Two Photon Absorption-Transient Current Technique (TPA-TCT) was employed to obtain information drift velocity electric field a LGAD different densities. TPA-TCT uses fs-pulse infrared lasers provide three-dimensional resolution bulk effects. A compact setup developed at CERN used measure current transients against device depth 285μm thick PIN LGAD, fabricated by IMB-CNM. Methods extract about are verify reduction. layer spatially resolved first time.