MBE Regrowth of a Laterally-biased Double Quantum Well Tunable Detector
Abstract
The main objective of this project is the development of a laterally biased QW IR detector. The structure is a double quantum well (QW) structure (fig. 1 a) consisting on a n-type doped QW tunnel-coupled with another n-type doped QW. Both wells are laterally contacted by means of two ohmic junctions (collector contacts) at the sides of the device. Furthermore, two pinch-off Schottky gates are deposited to reduce the direct conduction between the lateral contacts through the QW. This conduction is reduced applying an electric field to the pinch-off gate in a fashion similar to a field effect transistor for each one of the wells. When the electrons in the one of the wells are promoted from the ground state to the excited state (fig. 1 b), they tunnel out to the other well. The electrons in the biased well are then swept to the collector region by the lateral bias. It is also possible to apply a vertical bias (parallel to the quantum well heterostructure growth direction) using the bias gate. The major difficulty of this scheme is the deposit of the two contacts (bias gate and pinch-off gate) in the bottom part of the device. This should lead to the regrowth of the whole structure on top of a previously etched surface where the bottom contacts are defined. In this project we propose 3 different ways to the development of the mentioned device, they are summarized below.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2010
- Accession Number
- ADA544344
Entities
People
- Alvaro De Guzman Fernandez
- Rocio San Roman Alonso
Organizations
- Technical University of Madrid