Effects of Low-Energy Light Ion (H − ) Implantation on Quaternary-Alloy-Capped InGaAs/GaAs Quantum Dot Infrared Photodetectors

In Chap. 2, we showed that heavy ion (S−) implantations actually degraded the material and structural quality of InAs/GaAs QD systems, while there was an improvement in material quality when implanted with light ions (H−). We, therefore, decided to validate these results and study the effects of H− ion implantation on In(Ga)As/GaAs QD devices. Our research of interest was intersubband detectors. To validate the impact of ion implantation over devices, quaternary alloy-capped InAs/GaAs QDIP devices were implanted with low energy light ions (H−). Different steps to fabricate single-pixel devices are also discussed in this chapter. A suppression of dark current density was observed for the implanted devices. Moreover, we optimized the different properties of quaternary-alloy-capped multilayer InAs/GaAs QDs in Chap. 3. The use of growth engineering and implantation techniques introduced in this study made us expect better electrical characteristics from high-quality, well-formed dots.