Fig. 1: Band diagrams and transport characteristics of the PN junction and 2D SJ APDs.
From: Bilateral Geiger mode avalanche in InSe Schottky photodiodes
a Diagram device structure of a PN junction. P and N represent p-type and n-type semiconductor, while PN represent the depletion region of the PN junction. b Band diagram of a PN junction, showing the one-carrier multiplication process and dark current mechanisms. The shaded area represents the multiplication region. TAT and BBT denote trap-assisted tunneling and band-to-band tunneling, respectively. c The I-V curve for the PN APD. IGeiger, ILinear, and IR are the current of the Geiger mode, linear mode, and reversed saturation, respectively. d, e Diagram device structure and electron band structure of a 2D Schottky junction (SJ), showing the carrier multiplication process at the reverse and forward cases. The shaded areas represent the multiplication regions (depletion regions). f The I-V curve of a 2D SJ APD with bilateral avalanche breakdown. IDRI denotes the drift current.
