Analytical Modeling of Pinning Process in Pinned Photodiodes

In this paper, the pinning process of pinned photodiodes (PPDs) is described by a new analytical model, assuming the PPD to be composed of inner and junction regions. There are two definitions of the pinning potential: maximum conduction band potential variation (
$\Delta \varphi _{M}$
) and maximum electron quasi-fermi level potential variation (
$\Delta $
FP
$_{M}$
). The output of the previous pinning potential models is only an approximation of
$\Delta \varphi _{M}$
. In this paper, a comprehensive model is proposed in which both aforementioned definitions of pinning potential can be achieved analytically. The proposed model is a system of equations relating PPD’s main characteristics such as
$\Delta \varphi _{M}$
and equilibrium full-well capacity to other main PPD parameters such as PPD spatial dimensions, impurity dopant concentrations, maximum inner region potential, and remnant carrier population at
$\Delta \varphi _{M}$
. The proposed model is verified by two previously reported experiment-based data.