Photodetector with Controlled Relocation of Carrier Density Peaks: Concept and Numerical Simulation

Ivan Pisarenko,Eugeny Ryndin

doi:10.3390/photonics7010021

Abstract

Modern electronics faces the degradation of metal interconnection performance in integrated circuits with nanoscale feature dimensions of transistors. The application of constructively and technologically integrated optical links instead of metal wires is a promising way of the problem solution. Previously, we proposed the advanced design of an on-chip injection laser with an AIIIBV nanoheterostructure, and a functionally integrated optical modulator. To implement the efficient laser-modulator-based optical interconnections, technologically compatible photodetectors with subpicosecond response time and sufficient sensitivity are required. In this paper, we introduce the concept of a novel high-speed photodetector with controlled relocation of carrier density peaks. The device includes a traditional p-i-n photosensitive junction and an orthogonally oriented control heterostructure. The transverse electric field displaces the peaks of electron and hole densities into the regions with low carrier mobilities and lifetimes during the back edge of an optical pulse. This relocation results in the fast decline of photocurrent that does not depend on the longitudinal transport of electrons and holes. We develop a combined numerical model based on the Schrodinger-Poisson equation system to estimate the response time of the photodetector. According to the simulation results, the steep part of the photocurrent back edge has a duration of about 0.1 ps.

Highlights

The physical scaling of transistors and the enhancement of their integration degree have remained the primary trends of integrated electronics for many years
The device employs the principle of controlled relocation of carrier density
The relocation is controlled by the transverse electric field of the control density are caused by the reflection of electron and hole wavefunctions from the heterointerfaces in the heterostructure

Summary

Introduction

The physical scaling of transistors and the enhancement of their integration degree have remained the primary trends of integrated electronics for many years. We proposed the concept of on-chip optical interconnections based on original optoelectronic devices that combine the functions of lasers and optical modulators in unified AIII BV semiconductor heterostructures [14]. Drift-diffusion numerical simulation of conventional on-chip p-i-n, Schottky barrier and uni-travelling carrier (UTC) photodetectors demonstrated that their response time is restricted by semiclassical transport effects in AIII BV semiconductor materials and exceeds several picoseconds for the most efficient structures [17,19,20,21] Such performance is not sufficient for the adequate detection of short optical pulses generated by the lasers-modulators. The monolithic integration of such photodetectors with the AIII BV lasers-modulators cause multiple technological and design issues Their construction methods are not aimed at the response time decrease and exploit slow-response physical process (e.g., avalanche carrier multiplication in paper [24]). To estimate the response time of the device, we develop and implement a numerical model that combines the semiclassical current density formula and the quantum-mechanical Schrodinger-Poisson equation system

Photodetector with Controlled Relocation of Carrier Density Peaks

Numerical Model

Simulation Technique

Simulation Results and Discussion

Conclusions