Design of a voltage tunable broadband quantum well infrared photodetector
Approved for public release; distribution is unlimited === The purpose of this thesis is to design a quantum well infrared detector with tunable spectral bandwidth. The tunability of the bandwidth is achieved by using the linear Stark effect for the ground to first excited state transition in an asy...
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Monterey, California. Naval Postgraduate School
2012
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Online Access: | http://hdl.handle.net/10945/5896 |
Summary: | Approved for public release; distribution is unlimited === The purpose of this thesis is to design a quantum well infrared detector with tunable spectral bandwidth. The tunability of the bandwidth is achieved by using the linear Stark effect for the ground to first excited state transition in an asymmetric quantum well. The position of the absorption peak is dependent on the direction of the electric field, and therefore it can be either blue or red shifted by changing the direction of the field. If two identical asymmetric quantum wells are arranged opposite each other, we can obtain both the blue and red shift for either direction of the bias. This method can produce broader peaks with tunable bandwidths proportional to the applied field. A program was developed to calculate the energy levels and wavefunctions of an arbitrary quantum well. The program was used to design a step quantum well capable of detecting infrared in the 8-12 m m band. The validity of the approach was verified by comparison with experimental data and found to have a good agreement. The designed step well was used to create a tunable bandwidth detector. The analysis showed that the bandwidth could be tuned to more than twice the peak width. The numerical simulation indicates the possibility of manufacturing a tunable bandwidth infrared detector by using step quantum wells. |
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