Tuning in spectral response due to rapid thermal annealing on dot-in-a-well infrared photodetectors

• Published in: Superlattices and microstructures 2014-01, Vol.65, p.106-112
• Main Authors: Ghadi, H., Adhikary, S., Agarwal, A., Chakrabarti, S.
• Format: Article
• Language: English
• Subjects: Annealing; Dark current; Doppler effect; Epitaxial growth; Infrared; Mathematical analysis; Optical properties; Photodetectors; Semiconductors; Tuning; Wavelengths
• ISSN: 0749-6036; 1096-3677
• DOI: 10.1016/j.spmi.2013.10.036

The photoresponse peak was observed at 6.41μm for the as-grown device. As we increased the annealing temperature to 800°C, the peak response shifted to 9.52μm. •We investigated the effect of post-growth rapid thermal annealing on dot-in-a-well infrared photodetectors.•In a PL study, we initially observed a small red shift in the ground-state peak upon annealing at 650°C.•Then we observed the usual blue shift as the annealing temperature increased.•The spectral response peak was observed at 6.41μm for the as-grown device.•As we increased the annealing temperature to 800°C, the peak response shifted to 9.52μm. Here we investigated the effect of post-growth rapid thermal annealing (RTA) on dot-in-a-well infrared photodetectors. In a photoluminescence (PL) study, we initially observed a small red shift in the ground-state PL peak upon annealing to 650°C but then saw the usual blue shift as the annealing temperature increased. We also observed increases in the dark current as the annealing temperature increased up to 700°C but a sudden decrease in the dark current at 750°C. Activation energy is calculated using temperature-dependent PL and dark current measurements. The photoresponse peak was observed at 6.41μm for the as-grown device. As we increased the annealing temperature to 800°C, the peak response shifted to 9.52μm. Thus, we achieved wavelength tunability of peak photoresponse using the post-growth annealing technique.