Author(s): Wang, HM (Wang, Haomiao); Chai, HY (Chai, Hongyu); Lv, ZR (Lv, Zunren); Wang, H (Wang, Hong); Yang, XG (Yang, Xiaoguang); Meng, L (Meng, Lei); Yang, T (Yang, Tao)

Source: JOURNAL OF CRYSTAL GROWTH Volume: 578 Article Number: 126424 DOI: 10.1016/j.jcrysgro.2021.126424 Published: JAN 15 2022

Abstract: We report the effect of As flux rate (FR) during growth interruption (GI) after quantum dot (QD) deposition on the performances of InAs/InGaAsP/InP QDs and their lasers, grown by metal-organic chemical vapor deposition. The active region consists of seven layers of self-assembled InAs QDs separated by InGaAsP lattice-matched to InP. Room-temperature photoluminescence (PL) measurements show that both the PL peak intensity and emission wavelength of the active region increase with As FR. Temperature-dependent PLs reveal that the activation energies of the QDs from the ground state to higher energy level or barrier become greater with the increase of As FR, indicating less carrier thermal escape from the QDs to their barriers. These above observations can be attributed to the promoted migration and suppressed desorption of surface In atoms, leading to enlarged QDs with deepened energy levels and thus enhanced carrier quantum confinement effect. Moreover, a 6-mu m-wide and 3-mm-long ridge-waveguide QD laser with the greatest As FR shows a lowest threshold current of 477 mA under pulse mode at room temperature, corresponding to a threshold current density of 379 A/cm2 per QD layer. Meanwhile, the laser exhibits the highest characteristic temperatures T0 and T1 of 331 K and 775 K, respectively, in the temperature range between 20 degrees C and 60 degrees C.

Accession Number: WOS:000722187300008

ISSN: 0022-0248

eISSN: 1873-5002

Full Text: https://www.sciencedirect.com/science/article/pii/S0022024821003997?via%3Dihub