Switching between transverse electric and magnetic mode in InAs/AlGaAs/GaAs quantum dot infrared photodetector

By introducing a 2-nm-Al/sub 0.3/Ga/sub 0.7/As capping layer on the InAs quantum dots, a transverse electric (TE) field dominant response in quantum dot infrared photodetector (QDIP) has been achieved. The TE enhanced peaks are due to the transition from the S-like ground state to the P-like first excited states induced by the strain on the quantum dot. After rapid thermal annealing (RTA), the compressive strain changes. Therefore, the TE favorite peaks can be changed to transverse magnetic (TM) field enhanced and vice versa.