Optically controlled dual-band quantum dot infrared photodetector

TL;DR

This paper introduces a novel dual-band infrared photodetector that uses optically injected carriers to control the absorption spectrum of quantum dots, enabling tunable detection in the thermal infrared range.

Contribution

The paper proposes a new optically controlled dual-band quantum dot infrared photodetector and demonstrates its tunability through experimental and simulation results.

Findings

Two absorption bands at 5.85 um and 8.98 um were observed.

Absorption spectrum can be controlled by varying excitation power.

Experimental data aligns with simulation predictions.

Abstract

We present the design for a novel type of dual-band photodetector in the thermal infrared spectral range, the Optically Controlled Dual-band quantum dot Infrared Photodetector (OCDIP). This concept is based on a quantum dot ensemble with a unimodal size distribution, whose absorption spectrum can be controlled by optically-injected carriers. An external pumping laser varies the electron density in the QDs, permitting to control the available electronic transitions and thus the absorption spectrum. We grew a test sample which we studied by AFM and photoluminescence. Based on the experimental data, we simulated the infrared absorption spectrum of the sample, which showed two absorption bands at 5.85 um and 8.98 um depending on the excitation power.