Minimization of bandstructure dependent dark current in InAs/GaAs quantum dot photodetectors

Abstract

The paper presents a theoretical model which illustrates the electron capture and emission dynamics in InAs/GaAs quantum dot (QD) photodetector and describes the bandstructure dependent dark current generation. Result of the study predicts the possibility of excessive dark current that depends on the different rates of thermal and phonon assisted tunneling emissions from the quantized energy states. Variation of QD size can alter the quantized states and control the emission rates. Our findings shows that high dark current generated in a QD at a particular temperature and bias voltage can be reduced significantly by changing the size. Hence, optimum QD size is proposed that generates minimum the dark current at different temperatures of operation and applied bias. • Proposes a theoretical model on dark current generation in InAs/GaAs quantum dot photodetectors. • Illustrates modification of quantum dot size for altering the bandstructure. • Illustrates bandstructure dependent dark current generation mechanism at different voltages and operating temperatures. • Proposes optimizing the quantum dot size for minimizing dark current at different voltages and operating temperatures. • This work is a guideline for minimizing dark current and improve the performance of quantum dot photodetectors.