Learning Compact Physics-Aware Delayed Photocurrent Models Using Dynamic Mode Decomposition

TL;DR

This paper presents a novel approach using Dynamic Mode Decomposition to learn compact, physics-aware delayed photocurrent models from detailed simulations, enabling efficient large-scale circuit simulations.

Contribution

It introduces a method to derive reduced order photocurrent models that are both accurate and computationally efficient using DMD and physics-based simulation data.

Findings

Reduced models accurately replicate excess carrier dynamics

Models are computationally efficient for circuit integration

Demonstrated effectiveness in large-scale circuit simulations

Abstract

Radiation-induced photocurrent in semiconductor devices can be simulated using complex physics-based models, which are accurate, but computationally expensive. This presents a challenge for implementing device characteristics in high-level circuit simulations where it is computationally infeasible to evaluate detailed models for multiple individual circuit elements. In this work we demonstrate a procedure for learning compact delayed photocurrent models that are efficient enough to implement in large-scale circuit simulations, but remain faithful to the underlying physics. Our approach utilizes Dynamic Mode Decomposition (DMD), a system identification technique for learning reduced order discrete-time dynamical systems from time series data based on singular value decomposition. To obtain physics-aware device models, we simulate the excess carrier density induced by radiation pulses by solving numerically the Ambipolar Diffusion Equation, then use the simulated internal state as training data for the DMD algorithm. Our results show that the significantly reduced order delayed photocurrent models obtained via this method accurately approximate the dynamics of the internal excess carrier density -- which can be used to calculate the induced current at the device boundaries -- while remaining compact enough to incorporate into larger circuit simulations.