Growth and processing of III-V based infrared nanodevices


G. Strasser

A. Lugstein



This project is devoted to the investigation and optimization of optoelectronic devices based on quantum cascade lasers (QCLs) and quantum well infrared photodetectors (QWIPs), as well as to the growth and investigation of novel material systems and nanostructures like nanowires (NWs) and quantum dots (QDs). As an ultimate goal we aim to combine both fields and make use of the superior physical properties of novel nanostructures in opto-electronic devices. In addition to this P03 supplies the consortium with III-V NWs, QDs, QCLs, QWIPs and combined heterostructures for numerous electrical and optical investigations. P03 is organized in three work packages:

•    WP1 – Next generation III-V nanophotonic devices
•    WP2 – Novel material systems for infrared devices
•    WP3 – Growth and device integration of nanowires and quantum dots

WP1 – The investigation of advanced QCLs and QWIPs structures will deepen the understanding of the interaction between light and nanostructures, add functionality and improve device performance. Photonic crystals (PhCs) will be used for light coupling and as advanced resonators, plasmonic focusing of light to improve detector performance. The concept of smart-DFB QCLs will further be expanded to achieve phase locking in laser arrays for significant enhancement of spectral and spatial brightness. Integrating photonic crystal detectors and QCLs for lab-on-a-chip applications will open new avenues towards novel device concepts (collaboration with P02, P11, and P14).

WP2 – Novel materials and material combinations will be investigated for intersubband devices in the Mid-IR to THz range. This includes the combination of III-V with group IV semiconductors (in collaboration with P04, P05, and P08) and the combinations of semiconductors and metals. We will further exploit the recently developed type II material system (InGaAs/GaAsSb) for intersubband detectors and emitters. This material system is particularly interesting for THz devices (design and fabrication) and can be used to study the influence of the valence band to the device performance (from an experimental and theoretical point of view, in collaboration with P11 and P14).

WP3 – III-V NWs will be grown on group IV nanowires and on pre-patterned and planar substrates. We intend to study the growth possibilities/limitations of InSb nanostructures and Sb/As containing QDs and NWs (P08). Together with experimental (P08 and P11) and theoretical results from our collaborators (P13 and P14) we intend to design and realize emitter structures. We also plan to combine QDs and NWs with active devices like RTDs, QWIPs, and QCLs.