Multi-color Photoresponse Based on Interband and Intersubband Transitions in InAs and InGaAs Quantum Dot Photodetectors
- PDF / 220,164 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 103 Downloads / 245 Views
1055-GG02-02
Multi-color Photoresponse Based on Interband and Intersubband Transitions in InAs and InGaAs Quantum Dot Photodetectors Brandon S. Passmore1, Jiang Wu1, Eric A. Decuir, Jr. 1, Omar Manasreh1, Peter M. Lytvyn2, Vasyl P. Kunets3, and Greg J. Salamo3 1 Electrical Engineering, University of Arkansas, 3217 Bell Engineering Center, Fayetteville, AR, 72701 2 V. Lashkaryov Institute of Semiconductor Physics, Prospect Nauki 45, Kiev, 03028, Ukraine 3 Physics, University of Arkansas, 835 W. Dickson St., Fayetteville, AR, 72701 ABSTRACT The interband and intersubband transitions in self-assembled InAs and In0.3Ga0.7As quantum dots grown by molecular beam epitaxy have been investigated for their use in visible, near-, and mid-infrared detection applications. Devices based on InAs quantum dots embedded in an InxGa1-xAs (0 to 0.3) graded well and In0.3Ga0.7As quantum dots were fabricated in order to measure the temperature dependent (77 – 300 K) photoresponse. The dark current was measured in the temperature range of 77 to 300 K for the devices. Room temperature photoresponse ranging between 0.6 to 1.3 µm was observed for the InAs and In0.3Ga0.7As quantum dot photodetectors. Furthermore, a dual band photoresponse in the visible, near-, and mid-infrared spectral regions for both devices was observed at 77 K. Using a self-consistent solution of Schrödinger-Poisson equations, the peak position energies of the interband and intersubband transitions in the two multi-color quantum dot infrared photodetector structures was calculated.
INTRODUCTION The development of near-infrared (NIR) to far-infrared (FIR) detection is a key technology for many commercial, medical, military, and space applications, e.g., optical communication, smart fire alarms, detection of breast cancer, night vision and missile guidance [1]. In recent years, there has been much interest in using intersubband transitions in quantum dots (QDs) for mid-infrared (MIR) and FIR photodetectors (see for example [2] – [4]). Quantum dot based devices are expected to have superior optical properties compared to bulk and quantum well structures due to their three-dimensional carrier confinement. One advantage is the ability to absorb normal incident radiation which bypasses the need for corrugations or gratings commonly used in quantum well infrared photodetectors. This advantage eliminates unnecessary processing which in turn decreases the overall fabrication time and complexity. Other potential advantages are higher detectivities to infrared radiation and near room temperature operation which is a direct result of longer carrier capture and relaxation times due to the phonon bottle neck effect [5,6]. In addition, QDs do not have to be doped in order to observe photoresponse, consequently, reducing the dark current and noise. For non-equilibrium measurements, QDs are populated by the charge carriers that are generated from the contact layers and swept under the influence of a bias voltage. In this study, the photoresponse from interband and intersubband transiti
Data Loading...
