Defect annihilation-mediated enhanced activation energy of GaAs0.979N0.021-capped InAs/GaAs quantum dots by H− ion implantation

• Published in: Thin solid films Vol. 639; pp. 73 - 77
• Main Authors: Biswas, Mahitosh, Singh, Sandeep, Balgarkashi, Akshay, Makkar, Roshan L., Bhatnagar, Anuj, Subrahmanyam, N.B.V., Gupta, Shrikrishna K., Bhagwat, Pramod, Chakrabarti, Subhananda
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2017
• Subjects: Activation energy; Capping layer; Gallium arsenide nitride; Hydrogen ion implantation; Indium arsenide; Peak emission; Photoluminescence; Quantum dots; Hydrogen ion implantation; Quantum dots; Gallium arsenide nitride; Indium arsenide; Photoluminescence; Capping layer; Activation energy; Peak emission
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2017.08.026

Self-assembled InAs/GaAs quantum dots capped with GaAs0.979N0.021 quantum well grown on GaAs (001) substrates exhibited emission even beyond 1.5μm at room temperature. A low activation energy of 51meV was found, attributed to the incorporation of N into the capping layer. Rapid thermal annealing sufficiently improved photoluminescence (PL) intensity, but it causes strong blue-shift in the PL spectra due to In/Ga intermixing and N out-diffusion and slightly enhanced activation energy of 58.5meV. Because of the blue-shift and low activation energy, optoelectronic devices, where the design is based on a specific wavelength from the active layer, will automatically result in wavelength-sensitive failure. Implanting H– ions resulted in a two-fold improvement in the PL intensity without the blue-shift and also exhibited an activation energy of 71meV, attributed to the annihilation of defects via formation of N2H complexes. Thus, implanted samples are recommended for wavelength-sensitive optoelectronic device applications. •GaAs0.979N0.021 capped InAs/GaAs QDs exhibited emission beyond 1.5μm at 300K.•60-fold improvement in intensity after annealing, but blue-shift in emission spectra•H-ion implantation resolved the unwanted blue-shift caused by annealing.•A high activation energy achieved after implantation; defect annihilation.•Constancy in peak emission; application in lasers